Midterm #1 Flashcards
What is cognition?
Cognitive function, our thoughts and actions, is regulated by brain activity.
What is cognitive function primarily concerned with
Understanding the processes that produce complex behaviours.
Basic research
Goal is to understand the world and its phenomena without regard to a specific end-use of this knowledge. Understand how we perceive information, reminder, reason and solve problems.
Applied research
End-goal of developing a solution to a problem. Like improving education.
Hypothesis guided research.
We have a theory, from this theory develop a hypothesis (a guess between the link between variables). Must be testable against evidence.
Phenomenon-based research
An “effect” is discovered, and follow-up research examines the nature of the effect. Eg. Placebo effect.
Emotional enhancement effect
Emotional stimuli are more easily attended to, remembered than neutral stimuli.
Amygdala activity predicts memory for…
emotional but not neutral images.
Computational modelling of emotion
Help understand the processes that are involved in a current effect - then try to create algorithms that can stimulate emotions.
Benefits of computation modelling
If we can see these computations lead to the same effects we see in humans, then it might help us to get a stronger understanding of how emotion is processed in the brain and how that can affect tour behaviour.
Advent of AI
Chat GPT is an example of a large language model (an algorithm trained on human data to predict how we use language). Effective at mimicking human behaviour.
Historical approaches to studying cognition
Philosophical foundations from Ancient Greece - Rationalism and Empiricism.
The early days of psychology as an experimental science - Structuralism and Functionalism.
Behaviourism and then cognitive psychology - Focusing on only observation actions to accepting thought processes.
Philosophical foundations of cognitive psychology
Many Ancient Greek philosophers took an analytic approach to understanding the human mind by breaking it down into ‘parts’ to study.
Plato on cognitive psychology
First early philosopher to consider the human mind. Rationalism: knowledge is the result of observation & prior reasoning. Since internal thoughts and external observations interact, the world is a ‘reflection of our reality’. There is an innate aspect to mental processes and reasoning.
Aristotle on cognitive psychology
Combined philosophical and scientific approaches to thinking. Empiricism: all knowledge comes from experience. The basis of thought is forming associations based on observations.
Link between philosophy and cognition
Studying Philosophy: asking questions about how and why we think. Studying Cognition: gathering evidence to support the answers.
Structuralism
Identifying the basic building blocks of the complex thoughts or the conscious experience. Emphasized systematic, controlled observation for understanding the structure of the mind. Introspection is self-report.
Wilhelm Wundt and his goal
Founded the first formal laboratory for psychological research and practiced Structuralism. Goal: identify the simplest units of the mind that he thought followed certain laws to create complex thoughts. Asked what is the mind made of using introspection.
Wundt’s empirical introspection
Experimental self-report or observation about conscious.
Mental chronometry
Estimating time for a participant to perceive something. Eg: The thought meter
Criticisms of Structuralism
Simplistic approaches. Introspection considered too subjective, it is self report.
Functionalism
Asks why the mind works. Not interested in breaking down mental states to basic elements. Cognition is about serving a function and so must adapt to current goals. Focuses on the ‘usefulness of knowledge’. Emphasis on the adaptive functions of our mind. William James.
William James and pragmatism
Pragmatic: practical approaches to studying cognition. Opposed searching for basic mental elements. Believed that consciousness is personal. Emphasized an eclectic methodological approach.
Criticisms of Functionalism
Difficult to study some of these ideas (consciousness, imagery), especially if cognition is always changing.
Behaviourism.
Shift from studying the mind to behaviour. Focused on what can be observed (input, output). Did not consider mental processes. Focused on animal research because it is highly controlled.
Problems with Behaviourism
Overestimated the scope of their explanations. Cannot account for complex human behaviour. The assumption that learning is the same for all individuals and across species is false. Eg. Language.
The cognitive revolution
Accepted that there are internal mental states. Accepted the scientific method to study these states, like Behaviourism and other fields. Driven by technology.
Information processing view
The mind and brain is like a computer. 1. Info from environment is processed by a series of processing systems. 2. These processing systems change info in systematic ways. 3. Cognitive research aims to understand the processes and structures that underlie cognitive tasks.
Limits of information processing
The number of words remembered decreases as the distractor task increases in length. You cannot rehearse information and in that time, information is not processed.
Why do we process information?
To reduce uncertainty. The more uncertain something is, the longer it will take to process. The amount of info processed is inversely related to how much we expect that information to occur. (if we don’t know what to expect, we must process more).
Hick’s Law
The more information to process, the longer it takes to make a response to that information.
Choice overload bias
The greater number of choices (or uncertainty of choice) taxes information processes. Reduced satisfaction, lower confidence and more regret.
Decision fatigue
We have a limited amount of cognitive processing. Make decisions uses cognitive processing. Decisions become harder to make, and worse, thought the day.
Ecological validity
The extent to which the findings of research study can be generalized to real-life naturalistic settings.
The goal of cognitive research
The understand the computations made on information as a sequence of operations.
Assumptions of cognitive research
- Mental processes exist 2. Mental processes can be studied scientifically 3. We are active information processors 4. The basis of mental processes is the brain.
Mind-body problem
How are mental events related to the body (brain)?
Dualism on mind-body problem
The mind and brain are separate entities that are equally important.
Monism on the mind-body problem
The mind and brain are the same; Only one entity exists.
Dualism: Interactionism
Mind and brain interact to induce events in each other. Subscribes to the idea that we have a ‘soul’.
Rene Descartes
Interactionism. False idea that the pineal gland is this “principal seat of the soul”. Where the interaction between entitles occurs.
Dualism: Epiphenomenalism
Mental thoughts (mind) are caused by physical events (brain), but thoughts do not affect physical events. (One way interaction).
Monism
There is one basic entity that presents as both mental and physical responses.
Idealism
All reality is a mental construct, physical and mental.
Neutral Monism
The underlying nature is not mental or physical but something else, something neutral.
Materialism
All reality is the result of physical processes.
Neurons
Specialized cells that receive and transmit information
Nerves
Bundle axons that carry information long distances between neurons.
Glial glue Cells
Support cells for neurons
Central Nervous Systems (CNS)
Brain and spinal cord. Cognition primarily takes place here. Voluntary actions.
Peripheral Nervous System (PNS)
Outside the brain and spinal cord (body). Involuntary actions.
Peripheral nervous system: Somatic nervous system
Signals from brain to end organs. Voluntary control of muscle and senses.
Peripheral nervous system: Autonomic Nervous System
Up- and down-regulates involuntary bodily functions. Sympathetic and parasympathetic systems –> control of physiological responses in different ways.
Functional Specialization: Phrenology
Parts of brain correspond to mental functions and personality. Well-used mental functions: related brain area grows (bump). Under-used mental functions: related brain area shrinks (dent). False assumption that the highly developed functions have larger brain areas.
Functional localization / specialization
Modern neuroscience identifies brain area or networks that supports a particular function. Example: Fusiform face area (FFA).
Behavioural measurements to study brain-behaviour link
Behavioural experiments (voluntary responses). Psychophysiological measurements (involuntary responses): measure activity in the PNS in response to things that humans perceive or imagine (CNS).
Behavioural neuroscience methods for studying brain-behaviour link
Investigating neural underpinnings of actions (not cognition), typically with animal models.
Cognitive neuroscience methods of studying brain-behaviour link: Patient (Neuropsychological) Cases
Study brain function by comparing the behaviour of brain-injured patients to healthy control patients.
Split-brain patients (patient cases)
Examine processing differences between the two hemispheres of the brain. Left hemisphere supports language and speech, right supports visual-spatial processing.
Classic finding of split-brain patients
Info to the right visual field (left hemisphere) can be verbally named and described in words. Info to left visual field (right hemisphere) cannot be described verbally but can be expressed via visuospatial processes.
Cognitive neuroscience methods of studying brain-behaviour link: Neuroimaging techniques.
Examine change in neuronal communication that give rise to mental functions.
Behavioural neuroscience methods: Animal models
Investigating neural underpinnings of actions (not cognition) typically with animal models. Strength: provides a causal link between brain and behaviour. Weakness: doesn’t tell us about human cognition.
Electroencephalography (EEG)
A neuroimaging technique. An active brain produces electrical activity. EEG measures activity in a large group of neurons at certain times. Provides estimate about when brain is active. Use when we have questions about timing - but not about where.
Magnetic Resonance Imaging (MRI)
A neuroimaging technique. Structural MRI: anatomy of the brain (volume, location of grey matter), used to detect structural anomalies. Function (f)MRI: information about activity in the brain, and indirect measure as it measures blood flow and not neural activity.
Strengths and weaknesses of fMRI
Strengths: non-invasive, good spatial resolution, lots of replication and validation. Weaknesses: does not provide good temporal resolution, indirect measure of neural activity, very noisy.
Brain stimulation
Neuroimaging technique. Noninvasive method of changing brain activity that can inhibit or increase activity. A main form is Transcranial magnetic Stimulation (TMS) in focal magnetic field induces temporary change in brain activity.
Cognitive Neuroscience: Neuroimaging techniques summary (general)
EEG: Measure electrical activity with good temporal resolution.
fMRI: Examine Oxygen in blood flow with good spatial resolution.
Brain stimulation: Virtual lesions / modulation.
Greebles case study
fMRI was used to determine the level of activity in the fusiform face area (FFA) in response to faces and objects called Greebles (families of computer-generated “beings” that all have the same basic configuration but differ in the shapes of their parts). Observers were first shown both human faces and Grebes: indicated that the FFA neurons responded poorly to Grebes but well to faces. Then participants were trained in “Greeble recognition”: the FFA neurons then responded about as well to Greeble faces.
Sensation and perceptions flow
Sensation: Stimulus energy (light, sound, smell) –> Sensory receptors (eyes, ears, nose) –>
Perception: Neural impulses –> Brain (visual, auditory, olfactory areas).
Exteroceptive sensations
Any form of sensation that results from stimuli located outside the body detected by sensory organs.
Interoceptive sensations
Sensations from inside our body.
Synaestheisa
A neurological condition in which one sense automatically triggers the experience of another sense. Hear colours, smell sounds, see time. Genetic component. More common in women. Specific pairings tend to be stable over the lifetime of the individual.
Forms of synesthesia
Grapheme-colour synesthesia: colour with letter/numbers
Chromesthesia: Sound can evoke an experience of colour.
Why synesthesia is important
Represents the importance of individual differences. Encourages a view that brains are organized as “talking” circuits.
McGurk Effect
When you hear what you see. A multi sensory illusion. Illustrates integration of and cross-talk among senses. Illustrates the dominance of visual input.
Early visual processing
Sensation. Eyes and the optic nerve. 1. Light waves enter the eye - projected onto the retina - the retina forms an inverted image. 2. Retina photoreceptors convert light to electrical activity (Rods: low light levels for night vision Cones: high light levels for detailed colour vision.) 3. The electrical signal is sent to bipolar cells - send to the ganglion cells. 4. The signal exits through the optic nerve - to the brain for later visual processing.
Information compression
Millions of photoreceptors in each retina converge onto 100 or fewer ganglion cells
–> optic nerve –> brain. Input from the eyes to the brain is compressed.
Photoreceptor distribution
Cones are concentrated in the fovea (which is a small area on the central part of the visual field). So, centre of your visual field is most detailed.
Rods are mostly in the periphery, so the periphery of your visual field is less detailed and less accurate.
Blindspot
Photoreceptors are at the back of the retina; Ganglion cells are at the front. Ganglion cells make up the optic nerve that exists to the brain - must past the photoreceptor layer. At this ‘exit’ location, there are no photoreceptors - so no vision.
Why don’t we usually see our blindspot
Perceptual filling-in: later visual processes in the brain provide the missing info by ‘interpolating’ visual info from surrounding areas. The left and right visual fields can compensate for each other’s blindspot.
Early to late visual processing
Thalamus (later geniculate nucleus, LGN) is the way-station. The optic nerve of each eye transmits information to both hemispheres. Contralateral representation.
Contralateral representation
Left visual field is perceived via the right hemisphere. Right visual field is perceived via the left hemisphere.
Late visual processing
Perception. The primary visual cortex or occipital lobe. Specialized regions that process specific visual attributes or features (edges, angles, colour, light). Visual association areas interpret visual signal, assigns meaning.
Pathways to the visual association areas
What (ventral) pathway: occipital to temporal lobes. Shape, size, visual details.
Where (dorsal) pathway: occipital to parietal lobes. Location, space, movement info. Neuroimaging studies show separation of these pathways.
Ventral damage with intact dorsal stream
Impaired performance on visual object recognition or matching tasks.
Dorsal damage with intact ventral stream
Accurate performance on object recognition or matching tasks. Impaired performance on visual guided action (picking up an object appropriately).
Lessons from the visual system
Visual stimuli is altered at many stages of the processing pipeline. In the cortex, visual input is broken down, processed separately and then combined to form a perception of an entity. The reality we perceive is a construction of the brain.
Bottom-up processing
The influence of information from the external environment on perception. Info from sensory organs (eyes) to the visual cortex.
Top-down processing
The influence of knowledge (expectations, context, goals) on perception. Info from higher processing brain regions is sent back to the sensory organs.
Constructivist Theory of Perception
We use what we already know and expectations to predict how to perceive sensory information. Relies on the influence of top-down processes to vision. Illustrates how perception is an ‘illusion’. Support: the ponzu illusion, the monster illusion the world is lit from above illusion.
The letters in context effect
The ability to read words in sentences even when the letters in the middle of some words are mixed up. You ‘expect’ to see real words in a sentence.
The colour in context effect
The context a colour appears changes how you see that colour.
The sense of touch
Mechanreceptors –> Spine –> Somatosensory cortex. Cortical homunculus: spatially organized map of the body for sensory and motor.
Olfaction (smell)
Chemicals moving through the air pass through olfactory epithelium to olfactory bulb. Direct connections to memory and emotion brain regions. Smell has a stronger link to memory and emotion than any other sense.
Taste system
Works with olfaction. Taste buds on tongue, palate, pharynx, upper esophagus: measure chemicals that have been ingested. Relay message to thalamus and then the primary gustatory cortex.
What do bistable figures suggest
That we can experience spontaneous subjective change in perception.
Gestalt psychology
There are fundamental organizational principles to deal with ambiguity in our environment. These principles are based on knowledge and experience (top-down) and shared among people.
Gestalt organization principles
The principle of experience, Visual grouping principles.
Principle of experience
Figure ground segmentation: Image segmentation (figure-ground) depends on sensory input, detect edges or shadows - bottom-up. Experience and knowledge also drives figure-ground segmentation.
Visual grouping principles
Principle of proximity, principle of closed forms, principle of good contour, principle of similarity
Principle of proximity
Objects or features that are close to one another in a scene will be judged as belonging together.
Principle of closed forms
We see a shape in terms of closed forms, and we like to see items that enclose as as whole.
Principle of good contour
We perceive objects as continuous in cases where it is expected that they continue.
Principle of similarity
We organize objects or features of a scene based on similarity.
Direct models
Against the idea that ‘top-down’ processes are needed for perception. A passive bottom-up approach to perception. Sensory info is rich enough for perception. Requires an ecological approach to understand perception - study it in the real world. The ambient optical array (AOA) that reaches the retina has enough info to direct perception and movement. There are cues (computational tricks) in the AEA that are used too guide perception and action (bottom-up cues).
Examples of cues in the AOA
Topographical breakages: Discontinuity helps see edges and define objects.
Scatter reflection: How widely light scatters off an object’s surface provides cues about the nature of the surface.
Texture gradients: Near objects are farther apart and far objects are closer together.
Affordances
Cues indicate potential function of an object - visual cues in our environment. We ‘see’ based on what we can/need to do in the environment.
Damage to primary visual cortex: Blindsight
No conscious awareness (explicit perception) of visual objects in damaged visual field. Able to simplicity respond to questions about objects presented in the visual field. Suggests they can perceive something without ‘consciousness’.
Damage to the dorsal where pathway: Akinetopsia
Visual motion blindness: cannot see motion. Instead, perceives motion as a series of stationary objects.
Damage to the dorsal where pathway: Optic ataxia
Inability to reach for objects with the ability to name objects. Eg. problems reaching for a cup of coffee but can recognize the coffee. There might be action specificity in this pathway (selective damage leads to problems with certain types of movement).
Damage to the ventral ‘what’ pathway: Visual agnosia
Difficulties recognizing everyday objects. Difficulties can be selective to visual categories (faces).
Damage to the ventral ‘what’ pathway: Prosopagnosia
Fusiform face area (FFA) damage leads to selective deficit in recognizing faces, keeping intact the ability to visually recognize other objects.
The case of the sheep farmer.
Case study of sheep farmer with prosopagnosia. Unable to name or recognize famous faces or determine age or gender of human faces. Was able to recognize and discriminate sheep with high accuracy. There is selective face processing in the brain.
Damage to the ventral ‘what’ pathway: Apperceptive agnosia
Problems perceiving objects. A failure in recognizing objects due to problems with perceiving the elements of the objects as a whole. Problems with perception and discrimination of objects.
Damage to the ventral ‘what’ pathway: Associative agnosia
Problems assigning meaning to objects. An inability to associate visual input with meaning. Problems on tests that require accessing information from memory.
Feature detection theory
Visual input is broken down into individual parts (features). Each feature is processed sedately. The combination of features issued as a pattern for recognition.
Pattern recognition theory
Perception involves processing basic visual features of an input. We then add up these features and match it to existing patterns (concepts) stored in memory.
Template matching theory
Every object has a ‘template’ in long-term memory - too simplistic, computationally demanding. Cannot explain identification or classification.
Prototype theory
A prototype is the average representation of an object concept. Recognition is determined by ‘good enough’ match (resemblance). Allows for ‘flexible’ object identification.
Sound waves
Oscillating movement in the air caused by vibrations of objects in the environment.
Outer ear in sensing sound waves
Collect and focus sound waves. Pinna: Collected. Ear canal: focused.
Middle ear in sensing sound waves
Transfers and amplifies sound vibrations from outside (air) to inside (fluid). Ossicles: malleus, incus, stapes. Amplification problems? hearing aids.
Inner ear in sensing sound waves
Converts sound vibrations into neural signal (transduction). Cochlea. Basilar membrane: bottom membrane. Auditory Nerve. Transduction problem? Cochlea implants.
Tonotonic map
Location based on frequency of sound. Cochlea.
Sensation of sound
Auditory info goes to temporal lobe. Primary info goes to primary auditory cortex (organized in tonotonic map). Brain figures out what sound is in secondary auditory cortex.
Perceiving sound - pitch
Physical Property (Frequency Hz) –> Perceptual Property (Pitch)
Perceiving sound - loudness
Physical property (Amplitude dB) –> Perceptual Property (Loudness)
Perceiving sound - location
Sound hits your ears at different times. Intramural time difference: sound arrives at ipsilateral ear. Intramural level difference: Head shadow reduces sound level at contralateral ear.
Perceiving sound - auditory objects
Brain uses strategies to disentangle auditory streams.
Perceiving sound - emotion
Some sounds bring an obvious emotion. But some sounds have individual variation (chewing).
What is misophonia
Hatred of certain sounds. Decreased tolerance to specific sounds - like chewing.
William James on what is attention
Attention is best understood in terms of what it does rather than what it is.
Arousal Attention
Alertness and Awareness. Autonomic Nervous System; Reticular Activating System. Optimal: in the middle (moderate levels of arousal) - focused but not too narrow.
Bottom up attention
Stimuli guided by external factors. Something in the environment grabs your attention. TPJ; VFC
Top-down attention
Observer guided controlled attention.Voluntary. Know what to attend to, and also what to ignore. Frontal-parietal brain regions.
Neural mechanisms of attention
A network of regions across frontal and parietal lobes. Help brain prepare relevant neural activity for whatever you want to attend to.
Attentional shift
Shifting between attending to image vs. sound. They both activate top-down attentional regions.
Endogenous attention
When and individual chooses what to pay attention to (goals and attention). Top-down processing. Intraparietal sulcus (IPS) and FEF.
Exogenous attention
When stimuli in the environment drives us to pay attention. Bottom-up processing. Temporo-parietal junction (TPJ) and VFC.
Spatial neglect
Damage to the right hemisphere, ventral parietal cortex. Cannot attend or report stimuli on opposite side of lesion. Presents across sensory mechanisms and not just vision.
Balint Syndrome
Bilateral parietal and occipital lobe damage. Can’t focus on more than one thing. Can see local features, but struggle to see global features.
Top-down sustained attention
Maintain focus on one input for a long period of time. Vigilance.
Top-down divided attention
Shifting attentional focus between tasks. Multi-tasking.
Selective top-down attention
Focus on one input and ignore other information.
Why do we have selective attention
We have limited information processing resources.
Broadbent’s early selection filter model
You filter information at the level of perception, before information is processed for meaning (semantic analysis). Select info via perception, and selected info is processed for meaning, and then enters awareness. Information that is not selected by the filter will decay, and is not processed for meaning.
Dichotic listening task
Present two simultaneous messages to each ear. Participants better at recalling ear by ear than the simultaneous message. So, info is selected for attention, at perception.
Dichotic listening: Shadowing tasks
People do not remember the content of an unattended message, but they notice some sensory features. (A new noise, gender of the speaker). Evidence that unattended information is not processed for meaning but perception.
Evidence against early selection
In certain situations, un-attended information can “break through”. Eg. At a party, you can attend to one conversation, yet hear your name if spoken in a non-attended-to conversation.
Treisman’s attenuator model
An early filter dials down the influence of unattended material. Some aspects of unattended material to be processed for meaning.
Late selection filter models
We process input to the level of the meaning, and then select what we want to process further. An example of this is stroop task.
Controlled tasks
Those that require effort and voluntary top-down attention. Stroop: naming the colour of the ‘ink’
Automatic tasks
Those that are highly familiar and well-practiced and do not require voluntary top-down attention. Stroop: reading colour names
Interference effect on Stroop task
For the interference effect to occur on the Stroop task, you must process the written colour name (unattended information) for the meaning. This suggests that our attention is filtering at the level of meaning, not just at perceptual level.
Removing automatic processing
Hypnotized English-speaking participants to think colour names were meaningless (removes the automatic processing of meaning of the words). Result: No Stroop interference effect.
The load theory
Attentional filtering (selection) can occur at different points of processing. Filter placement will depend on how much of your resources are required for your current task. If low resource load, we process non-attended info to a later stage. If high resource load, we process non-attended info only to an early stage. * Less likely to be distracted by something if our main focus task is occupying a lot of our attention.
Two ways to define load.
- Central resource capacity: one resource pool from which all attention resources are allocated.
- Multiple resource capacity: Multiple resources from which attention resources are allocated. Attentional load depends the match between the relevant and irrelevant information.
Change blindness
The failure to detect changes in stimuli. Continuity errors in film.
Flicker technique paradigm.
Two similar visual images are presented with an interstimulus mask. Across trials, small changes are made to the images. Participants asked if something changed between the images. People are inaccurate.
Inattentional blindness
Not noticing something new in your focus of attention. A failure to attend to new or unexpected events in attended-to environment.
Measuring inattention blindness
Participants learn to focus attention to a particular space (do a task), then an unexpected target is presented in that space. Most say that they cannot spot the new target.
Functions of and ways to measure attention
- Pre-activating attention and the Posner spatial cuing task
- Integrating features and visual search
- Embodied theories of attention and measuring eye movements
Activating attention
Attention is about focusing on space and ignoring what is located ‘outside’ of the focused space. When moving attentional spotlight, disengage from current focus and shift to another area.
Posner cueing task
Fixate on centre of screen, then a cue will come up which will direct attention to an area, then measure reaction time to detect target. Two types: valid trial, invalid trial. Easier/quicker to detect target in valid trial.
Integrating features
Attention needed to integrate features to perceive and find objects. Demonstrates interplay of perception and attention. Feature-based attention evident during visual search tasks.
Two types of attention for integrating features tasks
- Pre-attention phase: Object features are separately coded. Bottom-up processing, automatic attention.
- Focused attention phase: Object features are integrated to guide a search. Top-down processing, voluntary attention.
Visual search tasks
Feature Search: Search for an object that differs from the distractors based on one feature. Bottom-up attention (automatic).
Conjunction Search: Search for an object that differs from distractors across many features. Top-down attention (voluntary).
The pop-out effect
Time to find a target that is different by one feature from distractors is independent of the number of distractors (set size). Only for features processed automatically in the visual cortex.
Embodied theories of attention
Eye movements detect visual attentional goals.
Overt visual attention
Attending to something with your eye movements.
Covert visual attention
Attending to something without eye movements
Cultural differences in visual attention
No difference in people spending time looking at objects, but people from Western culture spent less time looking at the background.
Sustained attention
The ability to focus on one task. Vigilance or concentration. Baggage scanners at the airport.
Divided attention
The ability to attend to more than one task; Multi-tasking. Restaurant serves who take orders, collect payments.
Divided attention: Task switching
Changing from working on one task to working on another task. Involves using top-down processes to switch between mental sets associated with each task.
Mental sets
Method of organizing information based on the goals. A tendency in how you approach situations or solve a task. Switching it requires attention.
Switch cost
Decline in performance (reaction time, accuracy) after switching tasks. The attentional system must be ‘re-set’ to engage the next task.
Attentional capture
Bottom-up cues - automatically processed. Eg. the sound of a car crashing, sirens. It is about surprise or a prediction error. Happens to info that is important for survival - adaptive for this info to be automatically processed. Many of these cues have functionally specialized processing regions in the brain.
What else capture’s attention?
Fearful stimuli, many with evolutionary roots. Personally relevant stimuli, such as our names. Addictive stimuli for individuals.
Measuring attentional capture
A modified go-no-go task. A ‘signal’ (circle) is presented under three conditions - superimposed in faces, objects, or nothing. Go trial: when the signal is green, indicate if there is a vertical line on the left or right of the image. No-go trial: when the signal is red, press a task neutral button, do nothing. The presence of human faces slowed down attentional processes for the go/no go task because they capture attention.
Mental Imagery
Our ability to mentally recreate perceptual experience in the absence of a sensory stimulus.
Dual-Coding Theory (Paivio)
Human knowledge is represented in two separate systems: Non-Verbal and Verbal
Non-verbal system
Modality-specific system. Based on sensory-motor information; Image systems. Images resemble what they stand for - analog representations. Maintain perceptual features of the stimulus they represent.
Verbal System
Symbolic system, Abstract. Language system. Information does not resemble what it stands for - abstract codes.
Depictive Representation Terms
Non-verbal representation. Analog representation. Depictive. Modal. Representations which maintain perceptual features of a stimulus. Eg. a photograph.
Abstract-Code Terms
Verbal representation. Propositional representation. Descriptive. Modal. Representations which have no direct connection to the features of a stimulus. Eg. computer code.
The Imagery Debate
We know that 1) People experience mental images 2) There are many ways that imagery influences cognition. The debate: What format or code does imagery take in our minds?
Kosslyn on the Imagery Debate
Images are dedicative representations. When you do mental imagery, you’re bringing the representation to mind.
Pylyshyn on the Imagery Debate.
Images are descriptive representations. Images as epiphenomenon: when you do mental imagery you hallucinate images as an effect of accessing the information.
Epiphenomenon
A mere by-product of a process that has no effect on the process itself.
Descriptive Processing (Pylyshyn, 1973)
Argues that knowledge is represented propositionally, via the manipulating of cognitive symbols. Argues propositional codes are the only requirement for thought. Propositions can be verified as true or false, can be used to describe relationships between items.
Do people process mental images in the same way they process real stimuli?
If images are depictive, then people should process images and physical stimuli similarity. If images are descriptive, then mental processing would depend on then umber of propositions instead of perceptual & spatial characteristics of stimuli.
Mental Scanning (Kosslyn)
If visual images are analog/depictive codes of physical stimuli, then:
1) It should take more time to travel longer physical distances than shorter ones.
2) It should take longer to process larger mental distances than shorter distances.
Kosslyn’s Mental Scanning experiment
Participants learned a map with landmarks. They were told to visualize one landmark, and scan the mental image until you have arrived at the target landmark. The time it took to mentally travel across landmarks increased with the “Distance” Number of propositional properties between landmarks remained constant. Evidence for depictive representation.
Mental Rotation (Shepard and Metzler)
Investigated the time it took for individuals to rotate mental images of abstract figures. If mental rotation is similar to the rotation of real objects, then it will take individuals longer to mentally rotate a greater angular distance compared to a smaller angular distance.
Results of Mental Rotation experiment
Results demonstrated a linear relationship between: amount of rotation of one of the shapes, and reaction time for participants to identify whether the shapes were the same or different. This is evidence for depictive representation.
Mental Scaling
When things get closer to you, they appear physically bigger until they fill your entire visual field.
Kosslyn’s Mental Scaling experiment
Participants imagined animals standing next to an elephant or a fly. Asked questions about the intermediary animal. Participants answered slower when the intermediary animal was paired with the elephant because they needed to mentally zoom in. Evidence for depictive representation.
Mary Perky experiment on imagery and perception
If imagery is perception without sensation, then it follows that imagery and perception should use similar cognitive mechanisms. She tested this by having patents mentally imagine stimuli, and they were then simultaneously shows a very dim image of the same item. Participants mental images matched features of the projection - they reported not consciously perceiving the image. This is evidence that imagery and perception utilize similar cognitive system
Segal & Fusella on Imagery and Perception
Visual and auditory stimulus (blue arrow, harmonica, or nothing) were presented at a very low intensity, making detection difficult. They had to indicate what stimulus was presented while either imagining a tree or a telephone ring.
Segal & Fusella on Imagery and Perception Results
Detection rates for the visual stimulus were lower when imagining a tree. Detection rates for the auditory stimulus were lower when imagining a phone ring. Imagining a stimulus “used up” resources, decreasing detection. Evidence that imagery and perception utilize similar cognitive systems.
Imagery facilitating perception
Presenting congruent stimuli enhanced detection performance. Evidence that imagery and perception utilize similar cognitive systems.
Arguments against depictive representations (Reed, 1974)
If mental images are depictive, they should easily be able to indicate if new shapes were part of the original from memory. His results showed that in some cases, participants were able to accurately determine if shapes were new or part of the original image, but in other cases the accuracy was quite low. According to Reed, these results could be explained if participants were giving verbal labels to objects, instead of storing spatial characteristics.
Experimenter Expectancy
Researchers inadvertently convey the anticipated results of the experiment to participants, altering behaviour.
Demand Characteristics
Participants form an interpretation of the researcher’s purpose and subconsciously change their behaviour.
Pylyshyn’s argument against Kosslyn’s results
Because participant performance in experiments on depictive representation varied depending on task details, Kosslyn’s results only supper their theory because that is what participants thought they’re supposed to do.
Imagery and the Brain
Neuropsychology is great, but it has limitations: generalized function loss, difficulty with instructions, damage to fibres of passage. New brain imaging technology lets us examine the brain in real time while an awake participant performs a cognitive task.
Evidence from neuroimaging
Neuroimaging results tend to support shared mechanisms between perception and imagery, although they are not exactly the same.
Paivio & Csapo experiment on Imagery and Memory
Asked participants to read words or to say the name of a picture out loud (verbal condition), OR, Imagine a visual image of the words and pictures (imagery condition). They were then given a surprise memory test. They found that image memory was better than word memory.
Dual-Coding Theory and the Picture Superiority Effect
When we see a picture, we automatically create a visual representation and give it a verbal label. When we read a word, we only generate the verbal label. Image based memory uses two codes (images and labels) instead of just labels.
The Concreteness Effect
Concrete words are remembered better than abstract words. Concrete words are easier to imagine, more likely to spontaneously create visual images. While abstract words are harder to visualize, so we rely only on one verbal code.
Imagery and PTSD
Negative intrusive imagery is a characteristic trait of individuals with PTSD. People will respond as if they are re-experiencing the event. People with more vivid imagery are more likely to experience intrusive images after negative events.
Imagery and Anxiety Disorders
Intense, persistent, and excessive worrying that interferes with daly life. Associated with an increase of negative imagery of future events, which they believe can happen, exacerbating anxiety.
Imagery and Depressive Disorders
Persistent feelings of sadness, frequently accompanied by a loss of interest. Associated with an increase of negative imagery, specifically suicidal ideation. Also associated with a decrease in positive imagery.
Imagery Rescripting
A technique to help treat mental disorders linked to abnormal mental imagery.Goal is to replace negative memories with positive ones.
Individual Differences in Imagery Ability
Great individual variation. Can measure mental imagery with self-report or objective performance tasks.
Aphantasia
Some people cannot form mental images at all. Patient MX claimed to have lost all ability following heart surgery.
Hyperphantasia
Individuals who experience extremely vivid visual imagery. More likely to occupy a creative procession.
