Science of the Mind

Science of the Mind

Disclaimer

• The majority of cognition research uses "WEIRD" participants:

  • Western
  • Educated
  • Industrialized
  • Rich
  • Democratic

• Many things are universal (brain structures, neurotransmitters), but not everything.

• Cultural and environmental differences exist (e.g., time perception).

• Consider cultural differences when interpreting research.

Modern Cognitive Psychology

• The scientific study of cognition:
  • Attention
  • Memory
  • Judgment
  • Decision making
  • Language
• Cognition is used all the time, often unconsciously.
• Cognitive psychology extends our understanding of how we use cognition.
• Originally, it was the scientific study of the acquisition, retention, and use of knowledge.

Introspection

• Wundt and Kitchener are credited with starting the introspection movement.
• Focus on the study of conscious mental events.
• Observation of events by looking inward to one's own experiences.
• Proposed that only trained individuals could introspect.
• Flaws:
  • Differences in worldview between people.
  • Differences within the same person over time.
  • Unconscious processing is common.
  • No way of falsifying (Karl Popper).
  • Subjective, not objective.

Behaviorism

• Watson and Skinner are credited with the starting of behaviorism, although Pavlov worked in the space earlier.
• Incorporated rewards, punishments, and reinforcement schedules.
• Stimulus leading to a response.
• Pavlov's dogs: associating bell with food.
• Problem: Cannot explain preferences, hopes, aspirations, or paint the complete picture.

Transcendental Method

• Using observable facts to work backwards.
• Observe behavior and hypothesize potential causes.
• Test hypotheses to see if the same effect occurs.
• Example: Seeing someone running and hypothesizing the reason (snake, fire, sale) and testing the hypothesis.
• Similar to the idea of "black boxes" in engineering.

Influential Forces

• Gestalt movement
• Frederick Bartlett and schema/schemata
• Noam Chomsky's contribution to language

Cognition as a Computer

• Emergence of technology provided a useful analogy for brain function.
• Use of terms like buffers, gates, processes.
• Valuable framework that feeds into psychology and neuroscience through networks.
• Cannot provide a 100% complete picture.

Measuring Cognition

Reaction Times, Error Rates, Variability, Hits and Misses

Digit Span Task

• Ebbinghaus credited with being the first cognitive scientist to use this task.
• Test of working memory.
• Participants recall a sequence of numerical digits correctly (forward or backward).
• Measured as the longest number of sequential digits accurately remembered.
• Normally developed adults: average span without error is 7 \pm 2.
• Originally proposed by Miller, seven chunks of short-term memory, plus or minus two.
• Children: Digit span task performance correlates with age.
• Adults: Memory span slowly decreases with older age and general cognitive slowing.
• Easier to recall numbers than letters.
• Performance not affected by word meaning, frequency, or complexity.
• Familiarity with subject matter improves memory.
• Phonological similarity effect: items with similar features are harder to remember.

Go/No-Go Tasks

• Based on the lexical position task.
• Measures capacity for sustained attention and response control/inhibition.
• Press a button (go) for some stimuli, withhold (no-go) for others.
• Example: Respond for even numbers, withhold for odd numbers.
• Tasks can become very complex.
• The primary measure is the commission error rate (making a go response for a no-go trial).
• Fewer errors signify better response inhibition.
• Average sample reaction times for university students are about 160 milliseconds for auditory stimuli and about 190 milliseconds for visual stimuli.

Psychomotor Vigilance Test (PVT)

• Introduced by Dinges and Powell in 1985; named after processes it measures.
• Cognitive task that measures sustained attention to give a numerical value of sleepiness.
• Responding to a visual cue presented at pseudo-random intervals (2-10 seconds).
• Mean reaction time is the most common measurement.
• Easy to score, simple metrics, good conversion validity.
• Used on the ISS to assess sleepiness.
• No cultural effects or learning effects; motivation can influence.
• Sleep deficits are associated with deteriorated alertness, slower problem-solving, declined psychomotor skills, and increased false responding.
• Impaired PVT performance can indicate sleep deprivation.
• Sleepiness and PVT performance may be improved with meditation.

Corsi Block Tapping Task

• Developed by Dr./Professor Corsi at McGill University in the 1970s.
• Watch the order in which blocks are tapped, then repeat the sequence.
• Online computer tests are now common.
• Start at two blocks and gradually increase to the maximum of nine.
• The average is only about five for this.
• Measures both the number of correct sequences and the longest sequence remembered, and that creates the CORSI span.
• Corsi span measures visual-spatial working memory (visual-spatial sketchpad and central executive).
• Parts this task taps into some very specific processes in cognition, primarily, it makes you use your ventralateral prefrontal cortex.
• No known gender differences in performance.
• Corsi span capacity appears to level out at age 14.

Navon Task

• Developed in the 1970s, measures global versus local processing.
• Global = forest (big picture), local = trees (details).
• Stimuli may be congruent or incongruent (e.g., large letter made of smaller letters).
• Global features are perceived first in Western cultures; even faster in East Asian cultures.
• Some remote cultures have local precedence.
• Global precedence is related to Gestalt principles of grouping.
• Kimchi Palmer task uses symbols (triangles and squares).
• Global processing: right hemisphere; local processing: left hemisphere.
• Don't go out and play golf after the navon task, it interferes with your golf parting ability.
• Performance affected by mood, OCD, and autism spectrum disorder.

Stroop Task

• First reported in 1929 by German researchers; attributed to John Ridley Stroop.
• Stroop's paper is one of the most cited papers in psychology.
• Neuropsychological test: name font color or word meaning as quickly as possible.
• Congruent: Word matches font color (e.g., the word "red" printed in red).
• Incongruent: Word does not match font color (e.g., the word "red" printed in blue).
• Measures delay in reaction time between congruent and incongruent stimuli.
• Trial numbers can vary from less than 20 to more than 150.
• Visual Stroop task: words and font color may or may not match the meaning of the word.
• Emotional Stroop task: emotional words presented in different colored fonts or words and facial expressions which may or may not match.
• Several areas of the brain are thought to be involved, primarily the anterior cingulate cortex known as the ACC and the dorsolateral prefrontal cortex.
• It can be influenced by age, environment and the placement of different types of furniture can affect performance in an educational setting.
• No concensus on gender effects.

Neuroimaging

EEG (Electroencephalography)

• Measures electrical activity in the brain.

• Neurons firing create small electrical currents.

• Fast Fourier Transform divides activity into bandwidths (alpha, beta, gamma).

• Different bandwidths represent different cognitive states.

• Requires analysis (event-related potentials, functional connectivity, band coupling).

• Advantages:

  • Non-invasive
  • Relatively cheap
  • Portable
  • Great temporal resolution

• Disadvantages:

  • Not good at spatial resolution

MRI/fMRI (Magnetic Resonance Imaging/Functional Magnetic Resonance Imaging)

• Good at spatial resolution; not good at temporal resolution (2-3 second delay).
• Uses BOLD (blood oxygen level dependent contrast).
• Ultra-fast fMRI (Chung et al., 2023) reported to work at sub-second level.
• Non-invasive but very expensive and non-portable.
• Not good for those with claustrophobia.
• Magnets: remove metal objects.

MEG (Magnetoencephalography)

• Best of both worlds: good at spatial and temporal resolution.
• Temporal resolution similar to intracranial electrodes.
• Measures magnetic changes associated with electrical currents in the brain.
• Non-invasive but very expensive and non-portable.
• Requires shielding from other sources of magnetism, including the Earth's magnetic field.
• Originally used SQUIDs; more recently uses SURFs (types of magnetometers).

PET (Positron Emission Tomography)

• Measures metabolic activity of cells (neurons).
• Nuclear medicine procedure: injects a tiny amount of radioactive substance (usually attached to glucose).
• Can be attached to oxygen, carbon, nitrogen, or gallium.
• Shows changes prior to other forms of neuroimaging (MRI).
• Provides earlier insight into Parkinson's disease, dementia (Alzheimer's), strokes, and epilepsy.

Neuromodulation

TDCS (Transcranial Direct Current Stimulation)

• Zaps the brain with an extremely low direct current (DC).
• Electrodes placed on the scalp deliver the zap.
• May have value as a treatment for major depressive disorder, anxiety, and PTSD (in some people).
• No evidence to support any role in cognitive enhancement.
• Side effects are generally minor (skin irritation, nausea).
• Avoid if you have epilepsy.

TMS/RTMS (Transcranial Magnetic Stimulation/Repetitive Transcranial Magnetic Stimulation)

• Uses a magnetic field to create an electric field that acts on the brain.
• Creates a virtual lesion.
• Can be used for therapeutic or diagnostic purposes.
• Benefits in the treatment of Alzheimer's disease, epilepsy, strokes, OCD, anxiety disorders, MS, and traumatic brain injuries.
• Generally safe; side effects include fainting.
• Caution: Pacemaker implants; magnets involved.