3.6. Neuropsychology
3.6. Neuropsychology
Bachelor-3 Psychology
Summary written by Amy van Wingerde
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,3.6. Neuropsychology
Theme 3
Sources
Attention
Kolb et al. (2015) – Chapter 22
Can I have your attention please?
Ziino et al. (2006), Michel et al. (2006)
Executive functions
Kolb et al. (2015) – Chapter 16
Who’s in control?
McDonald et al. (2002), Wright et al. (2012)
Attention
Kolb et al. (2015) – Chapter 22. Attention
- Attention is a property of the nervous system that directs complex actions of the body and
brain.
- They are not epiphenomena, properties that emerge simply because the brain is complex.
Defining attention
- Simple animals have limited sensory capacity and equally limited behavioral repertoire, and
primates (including humans) have even further developed sensory capacity and behavioral
complexity.
- And so, if sensory and motor capacities increase, so does the problem of selection of
information and behavior.
- We also need to combine all this sensory information into one whole (binding
problem).
- One proposed process for selective awareness and response to stimuli is attention,
narrowing of focusing awareness selectively to a part of the sensory environment or to a
class of stimuli.
- This process, the mental spotlight, may be conscious or unconscious.
- As sensorimotor capacities expand, so does the process of attention.
- Attention is primarily a top-down process that selects information from a specific part of the
sensory world.
Attention
- Attention has an uneven history, with behaviorists thinking that it is not a thing, and the
cognitive neuroscience that attention exists.
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, 3.6. Neuropsychology
Automatic and conscious processing compared
- Some behaviors can be done with little focused attention, whereas other behaviors are
highly sensitive to the allocation of attention.
- Automatic and conscious processing require at least some different cortical circuits, with
attentive processing including processes of consciousness.
Automatic processes
- Unconscious, direct behavior occurs without intention, involuntarily, without awareness,
and without interfering with ongoing activities, bottom-up.
- Bottom-up processing is data driven, it relies almost exclusively on the stimulus information
in the environment.
Conscious operations
- Controlled, effortful, attentive, and conscious, top-down.
- Top-down processing is conceptually driven, relying on information already in memory.
- Experiment of Treisman (1986): Visual processing task; Identifying a
target with an extra line is relatively easy and search time is
independent of the number of distractors, but when identifying a
target without the extra line, the time finding the target is dependent
on the number of distractors.
- From this, we can infer:
- Certain aspects of visual processing are automatic, we do not
need to focus attention, analysis only requires a specific visual
feature to locate the target.
- Other aspects of visual processing depend on focused
attention to locate the conjunction (combination of features);
conjunction search is a serial process searching for
combinations of sensory information.
- Although we can practice speeding up the feature processing,
it remains dependent on specific automatic neural associations
between features as well as serial-processing pathways.
- Treisman explained her results with the perceptual model of feature search, the cognitive
strategy for scanning for specific features of stimuli.
- Stimulus registered in area V1 is broken down into separate feature maps, this
information is then serially processed in parallel pathways, e.g. area V3, V4, or V5.
- Attention is directed to each location in turn and that features present in the same
fixation of attention are combined to form a single object.
- Attention is a glue that cements features into one single object.
- When the features have been assembled, the object can be perceived and held in
memory as a unit.
- Neurons outside area V1 and V2 respond differentially, depending on whether
attention is focused on the corresponding receptive field.
- Features are the properties the visual system codes cells to detect, maybe biologically
significant stimuli.
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