Consciousness (L4) Flashcards
Two versions of consciousness (Baumeister & Masicampo)
- Phenomenal (basic) consciousness: feelings, sensations and orienting to present moment.
- Higher consciousness: ability to reason, to reflect on one’s experiences, and have a sense of self.
Easy and hard problems
Easy problems of consciousness
- Measurable stuff: sensory input, motor output, verbal reports, neural correlates.
Hard problems of consciousness
- Linking these measured quantities to conscious experiences (qualia).
Controlled (conscious or explicit) processing (levels of processing)
The conscious use of attention and effort
- Slower, but more flexible (learning a new task)
Automatic (unconscious or implicit) processing (levels of processing)
Activities that can be performed without conscious awareness or effort.
- Fast, routine actions (walking, driving)
- Facilitates divided attention: the capacity to attend to and perform more than one activity at the same time.
Selective attention (Where’s Waldo) - what is happening? (4)
- Our eyes fixate momentarily on different parts of the visual scene.
- Then they saccade to different parts.
- We accumulate evidence as we conduct this saccade/fixate investigation.
- Eventually you identify Waldo.
The ‘cocktail party’ problems (2)
What is it called?
How do we focus on one speaker in a room full of speakers?
How do we take notice when something salient is said by one of the other speakers? (Like your name).
- This is called sound segregation.
Dichotic listening task (+ creator)
- Broadbent, 1958
- Two channels (ears)
- Participant must speak one channel out loud then recall as much information as possible from the other (ignored) channel.
Filter model explained
Broadbent proposed that multiple inputs are filtered based on physical properties, to select the most relevant.
- Meaning is processed after filtering.
Filter model limitations
It predicted that you should not be able to detect salient information from ignored channels.
However, you are able to shift attention if an ignored speaker is saying something interesting (e.g., your name).
Top down Modulation (plus bottom up signals that surpass it)
Top-down modulation underlies our ability to focus attention on task-relevant stimuli and ignore irrelevant distractions.
- Bottom up signals can still win out but require more salience:
1. Intensity (loud noise, bright flash, fast movement).
2. Arousal (such as through hearing one’s own name).
Top down modulation enhances input based on: (2)
- Relevance - to a task such as conversing with someone at a party, distracting input (other voices) are suppressed.
- Expectation - expected physical features of the other persons voice, the content of their sentences, their demeanour, eye gaze, etc.
Patient DF (condition & symptoms) (5)
- Visual agnosia
- Bilateral lesions to early ventral stream
Symptoms:
- Deficient object recognition
- Visual information could not be bound together.
- DF could not consciously visually perceive the shape, size, or orientation of the objects.
Prosopagnosia (what is it caused by?)
- Face blindness: patients can recognise objects but not faces.
- Show automatic arousal to similar faces, without awareness.
- Caused by damage to inferotemporal cortex (late ventral stream).
Optic ataxia
- Damage to the dorsal visual stream
- Symptoms: difficulty in using visual information to guide actions that cannot be ascribed to motor, somatosensory, or visual field or acuity deficits.
- Deficits with ‘how/where’ stream but not ‘what’ stream (can recognise objects).
Blindsight (3)
- Damage to primary visual cortex results in cortical blindness
- While patients cannot identify objects, they can often respond correctly to features of that object (motion, orientation, etc.).
- Info enters higher visual areas by the second pathway that bypasses V1 (via the pulvinar nucleus).
