lecture 2 - attention and distraction Flashcards

Question

Philosophical approaches to consciousness

Answer 1

- Historically there are 3 philosophical positions about the nature of consiousness (Block et al 1997). - 1 = consciousness is not a natural phenonmenon - not subject to the laws of nature that all scientists attempt to discover, laws involving matter and purely physical forces. The position states that consciousness is something supernatural and miraculous, not to be understood by the human mind. - 2 = consciouness is a natural phenonmenon but for various reasons we cannot understand it. Consiousness exists because of nature of human brain but its not known how it occurs. We can't understand consciousness because our brains are not capable of doing so. It needs a more complex brain than ours to understand the biology of subjective awareness. Alternative view = everything can be explained including all aspects of the human brain but consciousness is a vague, poorly operationally defined term. 3 = people are conscious and this is produced by the activity of the human brain and we should be optimistic about our ability to understand this phenomenon (Crick 1994).

Answer 2

- Its a private experience which cannot be shared directly. We experince our own consiciousness not others consiousness. We conclude others are consious as they are like us and they can tell us that they are. This has a subjective quality so makes consiousness difficult to study scientifically. - According to Velmans (2009), ‘the term means different things to many different people; there is no universally agreed “core meaning”’. - Chalmers (1995) suggests researchers face easy problems and a hard problem. Easy problems = ability to discriminate, categorise and react to stimuli, to intergrate info by using a cognitive system, to report mental states and to access internal states, to control behaviour delibrately and to differentiate between wakefulness and sleep. These are all associated with consiousness but chalmers thinks they are easy topics of consiousness as they primarily involve the contents of consiousness - theses features refer to functions or abilities. - Understanding (or discovering) the neural correlates of consciousness is also an easy problem, according to Chalmers. A mental state is said to be conscious when this state can be verbally reportable or internally accessible; the organism is able to be conscious of some information, react to it and explain it. This is another easy problem. - The hard problem lies in studying the experience of these mental events. Whne we report these mental events we have an experience of reporting these mental events. There must be something ‘that it is like’ to be conscious (Nagel, 1974); there is a subjective quality about it and because of this, it poses a difficult problem. These conscious experiences are sometimes referred to as phenomenal consciousness or 'qualia'. - Easy problems = understanding the functions and neurophysiology of consciousness Hard problem = explaining why we have the experience of consciousness in the first place

Answer 3

Neurobiological theories - Consciousness arises from the neural activity of the brain. - These theories derive their data from several sources eg neuroimaging and brain damage - and other branches of natural science, such as mathematics and quantum physics. Each type of study has a different perspective on the neural correlarates of consiousness

Answer 4

- Brain damage can alter human consciousness eg patients with anterograde amnesia are unable to form new verbal memories but can learn some kinds of tasks but are unaware they have learned something even when their behaviour indicates that they have. - Brain damage does not prevent all kinds of learning but does prevent conscious awareness of what has been learned. - Those who have damaged the posterior parts of the brain show a lack of awareness of stimuli presented to their visual field. Brain damage that impairs the perception of visual stimuli seems to also impair the ability. - Blindsight patients have damage to the primary visual cortex and they can perform some visual tasks they report being unaware of the task stimuli that had been presented in their visual field. - Individuals with certain types of agnosia are unable to recognise objects or may be unable to ascribe meaning to such objects. Another form of agnosia is characterised by the inability to identify familiar faces by using facial cues alone. All these disorders involve some lack of awareness and may help us to understand the regional contribution of the brain to conscious awareness. Blindsight patients, have damage to an area called V1, the primary visual cortex. This is the region in the brain to which information from the retina travels.

Answer 5

Crick and Koch (1995) have proposed the controversial idea that it does not. They argue that it is not involved in conscious visual perception because V1 does not directly project to the frontal cortex (which integrates information from other parts of the cortex); the areas surrounding V1, however – the extrastriate cortex – do, and it is the activity of these areas which may reflect conscious processing. Crick and Koch (1995) admit that this is a subtle and speculative proposal and have not undertaken an empirical test of this hypothesis.

Answer 6

- Brain damage from the surgcial procedure to releive symptoms of epilepsy which gives rise to split-brain patients or callosal syndrome - bogen 1993. neurosurgeons severe the corpus callosum to stop seizures occuring which is when violent storms of neural activity shift from one hemisphere to another via the corpus callosum. The patienst are therefore 'split-brain' to reduce the frequency of the seizures - sperry et al 1969. - Roger Sperry and Michael Gazzaniga and their associates (Gazzaniga, 1970, 1998; Gazzaniga et al, 1996; Sperry, 1966) pioneered research into the psychological consequences of split-brain surgery. Sperry won the Nobel Prize in 1981 for his work on neurosurgery. Their work, initially with cats, demonstrated that the cerebral cortex of the left and right hemispheres normally exchange information via the corpus callosum. With one exception, each hemisphere receives sensory information from the opposite side of the body and controls muscular movements on that side The corpus callosum allows these activities to be coordinated, so that each hemisphere ‘knows’ what is going on in the other hemisphere (Hoptman and Davidson, 1994; Banich, 1995). - After split-brain surgery, the two hemispheres of the brain operate independently and do not exchange information. - The effects of these disconnections are not immediately obvious to a casual observer. - The right hemisphere of an epileptic person with a split-brain can understand speech but is poor at reading and spelling. - Only the left hemisphere in most people controls speech. - Broca's speech area is located in the left hemisphere, making the right hemisphere incapable of producing speech. - Split-brain patients may experience alien hand, where their left hand seems to have a mind of its own eg patients may find themselves putting down a book held in the left hand even if they are reading it with great interest. The right hemisphere controls the movements of the left hand, leading to unexpected movements that puzzle the left hemisphere. One hypothesis suggests that the inhibition of actions organised elsewhere, but originating in the frontal cortex, is lost in split-brain patients, hence the appearance of unusual, uninhibited behaviour in one hand. One hypothesis suggests that the inhibition of actions organised elsewhere, but originating in the frontal cortex, is lost in split-brain patients, hence the appearance of unusual, uninhibited behaviour in one hand. - Intermanual conflict refers to the apparently contradictory activity of the left and right hands. - Akelaitis 1944/45 - When using their right hand to duplicate a geometrical design, split-brain patients often struggle and may be brushed aside by the left hand controlled by the right hemisphere. - The ability of speech mechanisms in the left hemisphere to receive information from other regions of the brain is crucial for consciousness as demonstrated by the effects of cutting the corpus callosum. If this communication is interupted then some kinds of information never reach consciousness. - The degree to which split-brain patients can make decisions about stimuli presented to the left or right of their visual field may depend on the part of the corpus callosum damaged: normally, not all of the corpus callosum is cut, only parts of it (Sergent, 1987, 1990, 1991). - In one study, two out of three patients when presented with circles in each hemifield could indicate which was bigger (Sergent, 1987). - There are other connections between the hemispheres aswell as the corpus callosum. Such patients may be able to undertake these tasks because of subcortical transfer, ipsilateral motor control, or communication via behavioural cues. Corballis et al (2018) note that there are many intact commissures, even cortical and cerebellar ones (Nomi et al, 2019), in split-brain patients. Perhaps it is the number of commissures that is cut that may be important (de Haan et al, 2020).

Answer 7

- Crick's theory (Cricks 1944) suggests that consciousness is the result of the activity of collections of neurons called neural assemblies = the astonishing hypothesis - The behaviour of neurones is represented by 35–75 Hz oscillations in the cortex which form the basis of consciousness and correlates with awareness in different sensory modalities. The theory suggests oscillation represents the way in which the information we process is bound. - Binding is important in consciousness and is the process whereby separate pieces of information about a single entity are brought together and used for processing later. (Chalmers 1995) eg bringing info together about colour and shape to form an image of an object. - Crick argues neural groups will oscillate in the same space and time when elements are bound together. Crick's theory has had attention and credit for tying consciousness to specific brain activity but has been criticised for not being able to explain the importance of these oscillations.

Answer 8

- Penrose’s (1989, 1994) model of consciousness relies on understanding quantum physics. - Quantum physics suggests that events are observable and follow a logical order and are altered by being observed, which is known as the Heisenberg Uncertainty Principle. - Hameroff and Penrose (1996) and Hameroff (1998) have suggested that consciousness takes place in the skeletal structure of neurons (called cytoskeleton), specifically in parts of the neuron called microtubules. - Hameroffs ideas are based of him being an anaesthetist and the process of anasthesia which induces loss of consciousness - Under general anaesthetic, individuals should not be able to move purposefully in response to a painful stimulus and should not be able to follow verbal commands. There is some controversial evidence that patients may be capable of remembering - In Hameroff's specific model of consciousness Microtubules are essential to consciousness as they transport material inside the neuron and define the shape of the processes that they inhabit so serve an important neural function. - Hameroff’s specific model of consciousness suggests that quantum events occur in or around these microtubules and these events give rise to our conscious experience. - The model can be criticised on the same grounds as Crick’s as it does not explain why such neural events should be associated with consciousness. - Churchland (1998) has suggested that microtubules might just as well be called pixie dust in the synapses – essence which magically gives rise to consciousness. - Hameroff (1998) has argued that the mechanism by which microtubules give rise to consciousness is detailed and not as vague as pixie dust. If these oscillations give rise to conscious experience, this is exactly Chalmers’s ‘hard’ problem,

Answer 9

Cognitive theories of consciousness, do recognise consciousness arises from the activity of the brain but describe the way in which consciousness occurs in mentalistic, cognitive terms.

Answer 10

- The global workspace theory states that the contents of consciousness are contained in a central processor called a global workspace which is used to mediate the activity of non-conscious processes. - When such processes need to inform the rest of the system, they send information to the workspace, which is a little like a blackboard used by the rest of the system (Baars et al, 1998). The model can explain how different types of conscious information are available to us but does not explain why this info in the global workspace is experienced so does not solve the 'hard' problem - Chalmers 1995

Answer 11

- Dennett's theory proposes that consciousness is not an all-or-nothing phenomenon that occurs in exactly the same way whenever it is evoked. - Dennett debunks the mind-body interactionism proposed by Descartes. - The notion of cartesian theatre where mind and body are interacting protagonists is untenable according to Dennett instead he argues consciousness is not a theatre its the activation of revised collections of sensory information called 'drafts'. - Because sensory information is received in various forms and at various times conscious experience is an updating, constantly revising process. - Therefore Conscious experiences result from multiple drafts of sensory information which are assembled at particular points in time. One criticism of dennetts theory is that, although it seems to abolish the notion of the Cartesian theatre, he is replacing it with many theatres

Answer 12

- Shanon's (1990,1998) theory claims that consciousness is not unitary and involves three components: sensed being, mental awareness, and reflection. - Sensed being distinguishes between animate and living, and inanimate and dead - mental awareness refers to the idea that we are aware of thoughts that pass through our heads, that is, we are aware of the contents of consciousness - reflection refers to the idea that we are aware of our mental computations and that these ‘mentations’ can be the subject of future ‘mentations’. - According to Shanon, there are two types of reflection: meta-observation which reflects on the content of mental states, and monitoring or control which checks and evaluates thoughts; this control guides or governs our thinking process. - According to Shanon, mental awareness is the core of consciousness whereas sensed being is a prerequisite and reflection is derived from it. - Shanon's theory is difficult to test as the components are vaguely and generally described. It is also open to the criticism that it is too descriptive and explains very little. Pierson & Triut argue that the ultimate function of consciousness is to enable volitional movement.

Answer 13

- We do not become conscious of all the stimuli detected by our sensory organs. - The process that controls our awareness of particular categories of events in the environment is called selective attention. - Sensory memory receives more information than it can transfer into short-term (working) memory. - Sperling (1960) found that although people could remember about 4 or 5 of the 9 letters he flashed onto the screen if they tried to remember them all they could direct their attention to any of the three lines of letters contained in sensory memory and identify them with perfect accuracy. - Selective attention serves to determine which events we become conscious of. - Attention may be controlled automatically, as when an intense stimulus captures our attention, it may be controlled by instructions, or controlled by the demands of the task we are performing. - Our attentional mechanisms serve to enhance our responsiveness to certain stimuli and to tune out irrelevant information. - We sometimes miss something important because our attention is occupied elsewhere. - According to Broadbent (1958) the brain mechanisms responsible for conscious processing of this information have a limited capacity. There is only so much information that these mechanisms can handle at one moment. Thus, we need a system to serve as a gatekeeper, controlling the flow of information to this system. - The nature of this gatekeeper - selective attention - is the subject of ongoing research. Our ability to detect the number of voices in a group is limited; we can usually identify no more than three - Vitevitch and siew 2016

Answer 14

- exclusion of auditory information has great practical implications. - Background noise is common in office environments and is a source of interference in open-plan offices (Klitzman and Stellman 1989) - Studies report that background office noise is associated with stress and lack of concentration, low levels of performance and reduced employee efficiency (Loewen and Suedfeld, 1992; Sundstrom et al, 1994). - Background noise does not interfere with every type of behaviour eg Music played in the background may even improve our performance. - Are there specific auditory stimuli, therefore, that selectively impair the performance of specific tasks? - For example, Salame and Baddely (1982) have suggested that performance on a cognitive task can only be disrupted if the disruptive auditory stimulus is speech. - others have suggested that stimuli other than speech can affect performance, giving rise to what has been termed the irrelevant speech effect (LeCompte et al, 1997). The irrelevant speech effect suggests that any disruptive sound (delivered at conversational level) can impair memory for verbal material during serial (that is, when the material has to be recalled in a specific order) and free recall (Salame and Baddeley, 1990; Jones, 1995). - Smith-Jackson and Kline conducted an experiment to discover whether irrelevant speech modified these responses.They set up an experiment in which participants completed a verbal task at a desk while irrelevant speech played behind them. In one condition, the speech was a conversation between two men; in another, the conversation of one person with pauses (as if talking on the telephone). The presence of irrelevant speech was associated with making a greater number of errors and longer completion rates. - An alternative to the speech effect is that the change state hypothesis that states noise which disrupts performance has to show some variation (rather than being speech-like) before recall is disrupted. (Jones et al 1992). Banbury and Berry (1998) found that office noise with speech and speech alone had a detrimental effect on memory for a prose passage whereas individuals in the office noise without speech condition performed no differently to a control group, suggesting that the speech component of the noise was important. All three noise conditions, however, were associated with deficits in arithmetic performance.

Answer 15

- Some early research suggested that the use of smartphones may not be advantageous for other behaviours such as academic performance, for example, especially among school children. - The dependency and the distraction, it seems, had a negative effect on a range of variables. - A study of over 2,000 middle and high school students found that smartphone dependency predicted poor maths and language performance (Seo et al, 2016); one study reported that when schools banned phones, academic low achievers were found to perform better (but high achievers’ performance did not change) (Beland & Murphy, 2016). - However, the results are not universal. Other studies find no detrimental use of smartphone use on academic performance, whereas some find no negative effect on learning but negative effects on non-academic outcomes (Lau, 2017). - One view argues that phones are so ubiquitous that their effects on any variable – unless directly related to the immediate environment – is negligible. - Many of these studies, of course, have different outcomes and all are correlational; they use one variable to predict another (because there is no way of experimentally inducing dependency in any way that is meaningful). A meta-analysis of the relationship between smartphone use and academic performance over the 10 years from 2008–2017 found that the effect of the former on the latter was very small, even where it did occur (Kates et al, 2018). The researchers also suggested another reason for any relationship a study is likely to find; perhaps those students who are more likely to use their phones/be dependent on them may be less likely to achieve compared to students who are not.

Answer 16

- Sperling's studies of sensory memory show the role of attention in selectively transferring visual information into verbal short-term memory/ into consciousness. Posner et al (1980) studied this phenomenon in detail and had participants watch a computer-controlled video display screen as a small mark in the centre of the screen served as a fixation point for the participants’ gaze. They were shown a warning stimulus near the fixation point followed by a target stimulus – a letter displayed to the left or the right of the fixation point. The warning stimulus consisted of either an arrow pointing right or left or simply a plus sign. The arrows served as cues to the participants to expect the letter to occur either to the right or to the left. The plus sign served as a neutral stimulus, containing no spatial information. The participants’ task was to press a button as soon as they detected the letter. - Eighty per cent of the time, the arrow accurately pointed towards the location in which the letter would be presented and 20 per cent of the time, the arrow pointed away from the location in which it would occur. - The advance warning clearly had an effect on the participants’ response times: when they were correctly informed of the location of the letter, they responded faster. - Study shows selective attention can influence the detection of visual stimuli - if a stimulus occurs where we expect it, we perceive it more quickly; if it occurs where we do not expect it, we perceive it more slowly. Thus, people can follow instructions to direct their attention to particular locations in the visual field. Because gaze remained fixed on the centre of the screen in this study, this movement of attention was independent of eye movement. - How does this focusing of attention work neurologically? The most likely explanation seems to be that neural circuits that detect a particular kind of stimulus are somehow sensitised, so that they can more easily detect that stimulus. In this case, the mechanism of selective attention sensitised the neural circuits that detect visual stimuli in a particular region.

Answer 17

- Inattentional blindness is a phenomenon where we fail to perceive visual stimuli when our attention is drawn elsewhere. (Mack and Rock 1998). - Inattentional blindness is similar to change blindness, where participants fail to notice changes in stimuli if their attention is directed elsewhere. - The inattentional blindness effect can occur in extraordinary contexts, such as a man in a gorilla suit walking across a basketball game screen while ptps count how many passes of the ball are made they don’t notice the gorilla. The advert is based on an actual experiment designed and conducted by Daniel Simons and Christopher Chabris (Simons and Chabris, 1999). The audience behaved as the participants in their study behaved and the inattentional blindness was seen for a man who walked across the screen carrying an umbrella and even for the gorilla when it walked along the screen, stopped in the middle, turned to face the front, thumped its chest, turned and walked to the other side of the screen. This segment took nine seconds. The whole film lasted 62 seconds.

Answer 18

- Various models have sought to explain divided attention and how we can (or, more often, cannot) undertake many tasks all at once. - Single-capacity models, for example, suggest that there is one pool of resources available to deal with perceptual and cognitive challenges (Kahneman, 1973). The more tasks an individual undertakes, the less capacity will be left to undertake these tasks effectively because each task is competing for the same pool of resources. Resources are, then, normally allocated to the most important task. - Single-capacity model theorists have found some support for this proposition in dual-task experiments (performing two tasks simultaneously). When this occurs, performance on both tasks diminishes. - The results suggest that when the resources necessary to complete tasks exceed the available single capacity, then performance will deteriorate. However, not all evidence supports this view. Experiments in which typists were asked to transcribe text and complete a shadowing task at the same time found the participants were able to do this effectively (Shaffer, 1975). Sometimes, two tasks can be performed as well as one can.

Answer 19

- An alternative model is the multiple resource models which argue we have several resource pools to deal with various cognitive and perceptual processes. It is because of these various pools that we can divide our attention between tasks successfully. - These models suggest that when two tasks compete for the same resource, this will result in an impairment in task performance. When tasks compete for different resource pools, then they should be performed successfully. A problem with the resource model, however, is operationally defining a resource and the types of tasks that would use the different ‘resources’. There is no general agreement on what the different types of resources are.

Answer 20

- For example, Johnston and Heinz (1978) suggest that selective and divided attention clearly requires some form of selection. They divide the type of selection required into early (selecting perceptual/sensory information) and late (selecting meaning). - Their process model does not agree that there is one structure or system which allows attention. It argues that early selection uses less capacity than late selection. - To test this hypothesis, they asked participants to undertake a dichotic listening task where the stimuli differed in terms of their physical features (perceptual) or in terms of their meaning (semantic). Concurrently, the participants undertook a reaction time task in which they had to press a button as soon as a light appeared. - The experimenters found that although reaction time was slower when the participants listened to two messages, less capacity was required when the messages differed perceptually (such as the speaker’s voice). - Only around 46 per cent of people report remembering any banner ads when they are asked to recall what was on a webpage they visited (Dreze and Hussherr, 2003). - Lapa (2007) found that over time, people learned where the location of the banners were and so avoided them on subsequent visits. However, even when the locations were randomised, people only fixated on them around 11 per cent of the time (Burke et al, 2005). - Would horizontal ads at the top of the page be better noticed than skyscraper ads going down the side of a page? And would an animated advert be better than a static one? The answer is that people fixate more on the skyscraper-type ad along the right-hand side of the page, especially if it is animated (Kuisma et al, 2010; Simola et al, 2011). A single animation was better than multiple animations.Animation reduces fixation on a horizontal ad. If an advert appears suddenly, people fixate on it for longer than if the advert appeared after around 12 seconds (Simola et al, 2011).

Answer 21

- The left and right cerebral hemispheres seem to play different roles in attention. - Focal attention (which involves attention to local cues) appears to rely on the left hemisphere, whereas global attention (a holistic approach which takes in whole objects or scenes) relies on the right hemisphere (Fink et al, 1996). - This asymmetry of function may explain the symptoms seen in the perceptual disorder, spatial neglect, in which brain-injured (usually right-hemisphere-damaged) patients are unable to report or respond to stimuli contralateral to the side of the brain injury. - Sustained attention has been associated with increased activation in the right prefrontal and parietal cortices, based on PET and fMRI findings, but generally there is a network of regions traversing the right fronto-parietal regions that are involved in sustained attention (Coull et al, 1996). - However, there is also evidence that the brain can adapt to what it sees, that is, after initial firing, this firing is reduced with repeated presentation of a stimulus. Thus, brain activation, measured via fMRI, is reduced when the same face or object is presented to the participant but recovers when the stimulus undergoes a modest transformation (Grill-Spector, 2009). - This increase and decrease appears to be associated with the firing of the inferotemporal neurons. - Selective attention has been associated with increases in activation in posterior regions, but the region of activation depends on the type of attention that is selectively applied. - If one sensory modality is attended to, regions associated with other modalities show suppressed activation (Haxby et al, 1994; Ghatan et al, 1998). - Divided attention also recruits the prefrontal cortex (PFC), especially the left (Vandenberghe et al, 1997; Benedict et al, 1998). - Posner and Petersen (1990) have characterised the ability to shift attention in three ways: the first component of attention allows the disengagement of attention from its current location (a function of the posterior parietal cortex); the second guides attention from the current location to the new location (a function of the superior colliculus, frontal eye fields and related structures); the third component allows the re-engagement of attention to the new location (a function of the thalamus). There is evidence that the lateral intraparietal area increases when people increase their attention to spatial locations and that an increase in the intraparietal sulcus is seen when people voluntarily direct attention to a location (Yantis, 2008).