PSYC 3160 Final Review

Which side of the brain is language processing lateralized?

Left lateralized

What are the stages of language processing (3, just names)?

1. Perceptual input and analysis

2. Internal processing

3. Output

In perceptual analysis of language, input could either be- (2)

1. Visual (written or signed words)

2. Auditory (spoken words)

How does internal processing of language work?

We have stored representations from prior learning, and we have processes for comparing inputs to representations

What are the 3 basic pieces of spoken language comprehension?

Sounds -> Speech -> Words

What are the steps of perceptual auditory input analysis?

1. Acoustic analysis (where sounds go through hair cells, cochlea, auditory cortex)

2. Convert that acoustic info to a phonological code- merging sounds into pieces of words

3. Using the auditory word info you have to access the lexicon

What is the hierarchy of processing regions for spoken language comprehension?

More inward towards primary auditory cortex (A1) = increased acoustic sensitivity (ability to tell apart sounds)

More outward towards temporal regions = increased speech sensitivity (ability to tell apart speech-specific sounds)

What was the study that demonstrated this processing hierarchy for spoken language comprehension?

Binder et al human fMRI study

Participants listened to sounds

IV- 5 conditions of sounds-

1. White noise (all frequencies)

2. Tones at specific frequencies

3. Reversed speech i.e. "riahc" (has same low-level auditory features as speech)

4. Pseudowords i.e. "prant" (sounds like it could be a real word in speech but no meaning)

5. Real words i.e. "chair"

DV- neural activity differences between conditions, interpreted a few different ways-

1. Acoustic sensitivity region = a region that can distinguish diff sounds, but not speech vs. tones

2. Speech perception region = (kind of a middle ground), a region that can distinguish between speech vs. tones, but not real vs. fake words (diff types of speech)

3. Speech sensitivity region = a region that can distinguish real vs. fake words (diff types of speech)

Results- found more acoustic sensitivity inwards towards primary auditory cortex; some acoustic sensitivity + some speech sensitivity around superior temporal gyrus (?); more speech sensitivity past superior temporal sulcus

What are the 3 basic pieces of written language comprehension?

Lines -> Letters -> Words

What are the steps of perceptual visual input analysis?

1. Visual analysis of lines

2. Converting that visual info to an orthographic code (letters)

3. Using that visual word info you have to access the lexicon (perceive words)

What is the word superiority effect?

We are generally faster to identify letters in real words than in fake words - knowing words supposedly influences how you perceive letters in a string

What kind of model did McClelland & Rumelhart propose for perception of words?

Model of both top-down and bottom-up influences (knowledge of words influencing perception of features/letters, knowledge of features/letters influencing perception of words)

What is global alexia? It is caused by damage to what area?

Impaired ability to read letters/numbers/symbols

Left hemisphere damage to medial + inferior occipitotemporal cortex (OTC)

What is pure alexia? It is caused by damage to what area?

Impaired ability to read words in a rapid parallel fashion, instead reads letter-by-letter

Left hemisphere damage to a portion of the left fusiform gyrus, called Visual Word Form Area

What was the study that investigated the storage of letters?

Puce et al human fMRI study

Participants viewed stimuli

IV- 2 conditions of visual stimulus type (1. faces, 2. letters)

Results- OTC activity for letters > faces (and fusiform face area activity for faces > letters)

Conclusion- OTC supports the conversion of lines to letters, and the storage of orthographic units (letters)

What was the study that investigated the storage of words?

Cohen et al human fMRI study

Participants viewed stimuli

IV- 2 conditions of visual stimulus (1. words, 2. letters)

Results- "Visual Word Form Area" activity for words > letters

Conclusion- VWFA supports the conversion of letters to words, and the storage of words

What is the mental lexicon?

An internal store of language information

T or F: mental lexicon is organized like a dictionary

False

What are the 3 elements of a word that help us to understand and use language?

1. Forms/sounds (i.e. O, W, L - plus sounds)

2. Syntactic info (i.e. noun)

3. Semantic info (i.e. bird, has wings, has feathers, etc.)

What are the steps of internal processing of the mental lexicon? (4)

1. Perceptual analysis (auditory or visual form of input)

2. Lexical access- activating representations in the mental lexicon (if already stored)

3. Lexical selection- choosing the best matching representation of what you have already stored

4. Lexical integration- when you combine a single word with larger sentence/structure/context (producing/processing spoken or written language)

What are the 4 organizing principles of the mental lexicon?

1. Units of meaning

2. Units of sound

3. Frequency (how often a word is selected)

4. Relation between words

What is a morpheme?

The smallest meaningful unit in a language; adding/subtracting morphemes changes meanings of words (i.e. frost vs. defrost vs. defroster)

What is a phoneme?

The smallest unit of sound that makes a difference to meaning; different languages have different phonemes--which sometimes don't map between languages (i.e. diff sounds for L and R in English vs. Japanese)

T or F: there's a critical period in life for recognizing certain phonemes

True- if you haven't heard certain phonemes by a certain point, you won't ever be able to distinguish them

What is a task that's used in the lab to study language comprehension?

"Lexical decision task"-(used to assess language comprehension and organization of the mental lexicon) participants are presented with a target and have to decide if it's a word of a non-word;

primary DV is reaction time;

it's been found that a word that shares phonemes with many other words takes longer to process than a word that does not share many phonemes (i.e. with the word "bat", you start with lexical access, then in lexical selection there are many other similar sounding words competing for selection)

How can the phenomenon of competition and selection in language be compared to motor control and attention?

In language (specifically Lexical Selection): words that share units of sound (phonemes) are simultaneously activated, leading to competition between words, slowing lexical selection

In motor control: Affordance Competition Hypothesis- action plans (what to do) and specification (how to do it) occur simultaneously, leading to competition between plans and selection from among competing plans

In attention: Biased Competition Model of Attention- because there is limited capacity and thus a selection process must occur, stimuli must compete with one another to be selected

Words of which frequency take longer to process?

Low frequency words (opposed to high frequency words)

What task in the lab can be done to investigate relations between words? What effect is observed with this task

Lexical decision task- have cues followed by targets, then ask if the target (second stimulus) is a word

"Semantic priming" is observed-- faster reaction times for related words relative to unrelated words

What does semantic priming suggest about the organization of the mental lexicon?

Suggests that mental lexicon is not just organized by sound (phonemes) but also by meaning (semantics)

What was the study that investigated how words are integrated into sentences?

Kutas & Hillyard human scalp EEG study

Participants read sentences, one word at a time (1 sec per word)

IV- 3 conditions of sentence type (1. Normal, 2. Semantically surprising given the context, 3. Perceptually surprising with something like all caps)

DV- voltage

Concluded that N400 supports semantic processing; P600 supports syntactic processing

How does the brain store abstract representations of knowledge? (organization name)

Sensorimotor organization- idea that semantic knowledge for a given object concept is built around its sensory and motor attributes; same system supposedly used for perception and for semantic memory

What was the study that investigated sensorimotor organization (+ how the brain represents concepts)?

Martin et al human PET study

Participants viewed grayscale objects

IV- 3 conditions of task type (1. Name the object, 2. Report its color, 3. Report action of object)

DV- brain activity, interpreted in a few diff ways (region representing knowledge of colors, of actions, of both colors and actions)

Results- V4 responds more to color knowledge, V5 responds more to action knowledge

Conclusion- suggest that the brain regions that support the perception of particular feature also appear to store the KNOWLEDGE of those features

How are sensorimotor properties organized? How was this found?

Seems to be an "amodal" (not modality-specific) hub that combines all sensorimotor properties

Found through patients with failure in recognition (recall that apperceptive and associative agnosics cannot recognize objects by sight; have a modality-specific impairment of vision)

What is semantic dementia? What regions of the brain are damaged with this?

Failure to identify objects regardless of the perceptual modality (sight/sound/touch)

Damage is typically in the anterior/lateral temporal lobes

What region is known as a semantic hub?

Anterior temporal lobe (ATL)

(activated across all recognition tasks)

What is Broca's aphasia?

(e.g. Patient Tan, where speech was effortful)

Deficits in both language production and comprehension

("agrammatic aphasia"- difficulties understanding in the context of grammar)

What is Wernicke's aphasia?

Deficit in language comprehension; exhibit fluent but nonsensical speech

("semantic paraphasia"- substituting different word for intended word)

T or F: Patients with damage in just Broca's region exhibit the full symptoms of aphasia

False

T or F: Patients who demonstrate the full symptoms of aphasia have more extensive damage than just Broca's/Wernicke's area

T

What area is damaged with Broca's aphasia?

Left prefrontal cortex

What are is damaged with Wernicke's aphasia?

Left temporal/parietal cortex

What is cognitive control? (4 components)

1. Planning + creating subgoals to achieve an abstract goal

2. Maintaining a goal + using it to direct behavior / Flexibly updating goals

3. Attending selectively to relevant info (selecting a weaker task-relevant response over a stronger task-irrelevant response)

4. Monitoring control and detecting errors

What is NOT considered cognitive control?

Habits which are automatic + stimulus/context driven

What is the Stroop task?

Participants view colored words

IV- 2 conditions for task type (read word, name color), 2 conditions for stimulus type (congruent, incongruent)

DV- reaction time

Results- higher reaction time for incongruent stim and name color task

One interpretation- word reading is "automatic" or "habitual," and color naming requires CONTROL

How are the components of control seen in the Stroop task?

Maintaining + flexibly updating goal --> Naming the color

Attending to only relevant info --> Ignoring what the letters say, not reading the word when that's not the task

Monitoring conflict + detecting errors --> Naming color with incongruent word and color

Damage to what area causes deficits in cognitive control?

PFC

What are the abilities associated with an intact PFC? (4)

1. Perception

2. Motor skills

3. Speech and language

4. Memories, knowledge, intelligence

What are the observed deficits in cognitive control when PFC is damaged?

1. Failure of goal-planning

2. Utilization behavior (using a stimulus regardless of situational appropriateness)

3. Perseveration (maintaining a goal when it's no longer relevant/appropriate)

What was the study that investigated whether the PFC maintains and updates goals (task-switching)?

Braver et al human fMRI study

Participants make (semantic) decisions about words

IV- 2 conditions of goal (switch-goal trial or same-goal trial)

If a region supports goal updating, it should show increased activity for switch-goal trials, relative to same-goal trials

Result- found an area in PFC where activity increased when switching between goals

Which region in the PFC activates when switching tasks/updating goals?

Left inferior frontal gyrus (LIFG)

In terms of cognitive control, what is selection?

Ability to focus attention on external perceptual features or internally maintained information

What is meant by the term dynamic filtering mechanism? What region is classified this way?

Region that takes all of the attended or maintained info and selects what is goal-relevant

PFC thought to be this way

What was the study that looked at brain activity during selection tasks?

Thompson-Schill et al human fMRI study

Participants make semantic decisions about word

IV- 2 levels of selection (high, low)

Results- found region which showed greater activity for high selection vs. low selection, so it's thought to support selection processes

What region is thought to support selection processes?

Left inferior frontal gyrus (LIFG)

What was the study that investigated the necessity of LIFG for selection?

Same team that looked at brain activity for selection tasks- Thompson-Schill et al human lesion study

Participants do "generation task," saying what the object does or what you do with it

IV- 2 levels of selection (high, low)

DV- number of errors made (representing inability to retrieve an appropriate verb)

Hypothesis #1: LIFG is for generation/word retrieval (if true, patient should be impaired in both high/low selection conditions)

Hypothesis #2: LIFG is for selection (if true, patient should be impaired specifically for HIGH selection condition)

Results: found most errors with LIFG lesion patients in high selection condition...

so LIFG must support selection

What was the study that asked if selection is the result of enhancement of task-relevant info or inhibition of task-irrelevant info?

Gazzaley et al human fMRI study

Participants view faces and scenes

IVs- 3 conditions of stimuli to be remembered

DV- activity in face- and scene-selective regions (not PFC)

Passive viewing served as a baseline (for PPA and FFA activation with perceptual input); task is to try to remember scenes, ignore face; then next task is vice versa

How much does FFA/PPA activity change as a function of selection?

Hypothesis #1: if control enhances task-relevant info, PPA activity should increase when scenes are to be remembered, and FFA activity should increase when faces are to be remembered

Hypothesis #2: if control inhibits task irrelevant info, PPA activity should decrease when faces are to be remembered, and FFA activity should decrease when scenes are to be remembered

Results- both hypotheses are supported!

When is selection required?

When stimuli, representations, and/or responses compete

How is selection in cognitive control similar to the Biased Competition Model of Attention?

Attention changes neural signals and behavioral performance when stimuli compete for attention;

Control changes neural signals and behavioral performance when stimuli compete for selection

How does selection in cognitive control differ from attention?

With cognitive control, need a way to detect and resolve competition

What region supports conflict monitoring? (general region + more specific region)

Medial prefrontal cortex; specifically the anterior cingulate cortex (ACC)

How do we know that the ACC monitors conflict? (2)

1. Has connections to many other brain regions; can "listen in" to what's going on

2. Shows a negative voltage deflection after an error is made

What was the study that investigated conflict monitoring and response conflict in the brain?

MacDonald et al human fMRI study

Participants did modified Stroop task (had instruction phase, then stimulus phase when word is shown)

IVs- 2 conditions of stimulus type, 2 task conditions, 2 prefrontal regions measured

Delay was used to separately examine 2 components-

1. Goal updating/maintenance during instruction phase

2. Response conflict monitoring during stim phase

If region shows goal maintenance/updating sensitivity, will have more activity for name-color than read-word task (specifically during the instruction phase);

If region shows response conflict sensitivity, will have more activity for incongruent than congruent stimuli (specifically during the stim phase)

Prediction 1: lateral PFC (LPFC) should show greater goal sensitivity

Prediction 2: ACC should show response conflict sensitivity

Results- predictions supported; double dissociation - goal maintenance + response conflict --> independent processes! (supported by different prefrontal regions)

What are goal-oriented decisions?

Decisions made on the assessment of expected reward or the value of an action

What are action-outcome decisions?

An action is made based on the evaluation of expected outcomes

What are stimulus-response decisions?

A response is made based on the presence of a stimulus

What is value's role in decision-making?

The ability of an outcome to reinforce a behavior depends on that outcome's value

T or F: Value = magnitude/payoff of a reward

False (not fully true); value is not just the magnitude/payoff of a reward, but also the probability + the effort/cost

What is delay discounting?

The phenomenon in which the same reward magnitude has a lower value at longer delays

What was the study that investigated how value is represented in the brain?

Hare et al human fMRI study

Participants were self-reported "dieters"; engaged in a rating phase (rated 50 diff foods for taste + for health), engaged in a decision phase (choose between diff foods)

IVs- 1) Goal values (taste, health)

2) Whether participants were self-controllers or non-self-controllers (based on choices)

Had a reference item (participant-specific, determined by rating phase-- what they said was neutral taste + neutral health); at decision phase, compared foods w/ reference item

Prediction 1: People who are self-controllers will choose the reference item over the unhealthy tasty item

Prediction 2: People who are non-self-controllers will choose the unhealthy tasty item over the reference item

Results- found brain region with greater activity for high vs. low value items; also found that value sensitivity to taste vs. healthy differ across self- and non-self-controllers

What was the brain region that was found to have value-sensitivity?

Orbitofrontal cortex (OFC)

When is OFC activity higher for self-controllers? For non-self-controllers?

Self-controllers: OFC activity higher when food is healthier

Non-self-controllers: OFC activity higher when food is tastier

What was the control-sensitive region that Hare et al found?

Left LPFC

*(greater activity in LPFC in control trials for self-controllers vs. non-self-controllers)

What factors can control OFC activity? (2)

Individual's values

Individual's control

What is the Rescorla-Wagner model for learning value? What does each variable of the model represent?

Vt = (α * (Lt - Vt-1)) + Vt-1

Vt = value on trial t

α = learning rate (a constant)

Lt = reward obtained on trial t

Vt-1 = value on trial t-1

Interpreting each variable of the Rescorla-Wagner Model, what is value based on?

What happened (Lt) compared to what you expected (Vt-1) scaled by how much you learn (α) from any given trial

What does it mean if α = 0?

Learning rate = 0; you learn nothing, and value never changes

What does it mean if Lt = Vt-1?

When outcome matches your expectation; you learn nothing, and value doesn't change

According to the Rescorla-Wagner Model, what leads to large changes in value?

Large differences in expectation and outcome

(assuming that learning rate α is between 0 and 1)

According to the Rescorla-Wagner Model, when does the most learning (biggest change in value) occur?

When outcomes are surprising and there is a "prediction error" (when outcomes don't match expectations)

What are the primary dopamine centers in the brain? (2, 1 expanded)

1. Substantia nigra (SN)

2. Ventral tegmental area (VTA); projects to the Nucleus accumbens (NAcc); the NAcc = part of Ventral striatum

What evidence do we have for the VTA's connection to dopamine and reward?

Old & Milner experiment- rats were placed in skinner box w/ electrical stimulator, lever, electrode

When electrode was placed on the VTA- found that rats would self-stimulate at the expense of food, sometimes stimulating until they die!

How have we disproven that dopamine = reward signal?

An increase in dopamine doesn't always lead to an increase in the behavior; stimulation of dopamine neurons in the indirect pathway DECREASES behavior

Dopamine doesn't always increase in the presence of reward; it doesn't increase during an expected reward (e.g. a US)

Punishments do induce dopamine changes; dopamine neurons fires LESS following an unexpected punishment/loss

What was the study that disproved that increasing dopamine always leads to increase in a behavior?

Kravitz et al rodent stimulation study

Mice placed in box with 2 levers (one lever turns on a laser to stimulate cells, the other does nothing)

IV- whether the direct or indirect pathway of basal ganglia is stimulated

DV- % of trials on which the mouse presses the lever connected to the laser

(Review of b.g. circuitry:

Primary NT = dopamine;

Different types of dopamine receptors (D1, D2);

SNc excites the direct pathway + inhibits the indirect pathway;

Creates a "gatekeeping" system)

Results- stimulation of dopamine neurons in INDIRECT pathway of b.g. DECREASED behavior!

Conclusion- found evidence against increase in behavior with increasing dopamine

What was the study that disproved that dopamine increases anytime a reward is present?

Schultz et al monkey single-unit study

Monkeys did classical conditioning task, where bell predicts juice

IV- whether the monkey expects/predicts the reward

DV- firing rate in VTA neurons

Results- dopamine did not increase with expected reward (the US, juice, being predicted by the CS, bell)

What was the study that disproved that dopamine is not affected by punishment?

Zaghloul et al human single-unit study

Participants did card deck selection task (each deck had a diff reward probability-- goal was that they learned these diff reward probs and started choosing accordingly)

IVs- 4 conditions of expectations/feedback-

1. Expected gains

2. Expected losses

3. Unexpected gains

4. Unexpected losses

DV- firing rate of substantia nigra (SN) neurons

Prediction 1: If dopamine represents reward, SN firing rate should change for conditions 1 and 3

Prediction 2: If dopamine represents prediction errors, SN firing rate should change for conditions 3 and 4

Results- dopamine neurons fired LESS following an unexpected punishment/loss (unexpected gain); prediction 2 supported!

What is dopamine thought to represent? What evidence do we have for this?

A prediction error signal

Dopamine doesn't increase during expected gains/rewards, but dopamine DOES change during unexpected losses

What was the study investigating how dopamine impacts learning?

Frank et al human lesion study

Looked at reinforcement learning in Parkinson's disease

Participants did standard Japanese characters task (so these symbols don't have value for American participants); goal was to obtain rewards (should start to learn which symbol yields more rewards)

IV- reward feedback (positive or negative), patient group (on L-DOPA or off L-DOPA--precursor to dopamine) (age matched controls!)

Hypothesis- non-medicated PD patients shouldn't be able to learn from positive feedback, but could learn from negative feedback; medicated PD patients shouldn't be to learn from negative feedback, but could learn from positive feedback

In addition to learning/feedback phase, had test phase

Results- hypothesis supported! -- enhanced "no-go" (avoid) learning in unmedicated PD patients; enhanced "go" (choose) learning in medicated PD patients

What is an emotion?

A valenced response to external stimuli and/or mental representations; caused by changes across multiple systems

How is an emotion different from a mood?

Emotions are more transient in time; mental health issues can be referred to as mood disorders

T or F: Emotions are either learned or unlearned

True

What are the 6 basic emotions?

1. Anger

2. Happiness

3. Disgust

4. Surprise

5. Sadness

6. Fear

What are the criteria for basic emotions (according to Paul Ekman)?

1. Presence in other primates

2. Distinct from other emotions; has universal signals (i.e. smiling with happiness), distinct physiological responses (i.e. sweating in fear), ties to thoughts/memories/imagery

3. Automatic/uncontrolled; rapid onset, brief in duration, automatic appraisal process (brain figures out automatically what emotion is being processed/experienced), unbidden occurrence

What are the dimensions of emotion? (2)

1. Valence (negative vs. positive)

2. Arousal (high vs. low)

What are theories of emotion generation? (4, just names)

James-Lange theory

Cannon-Bard theory

Singer-Schacter theory

LeDoux's high/low road theory

What is the James-Lange theory of emotion?

Arousal then conscious emotion (serial process)

e.g. Oncoming car -> ANS arousal, body changes -> conscious fear

(You decide your emotion bc of your body response)

What is the Cannon-Bard theory of emotion?

Arousal AND conscious emotion (parallel/simultaneous process)

e.g. Oncoming car -> ANS arousal + conscious fear occur at once

(You decide your emotion at the same time as your body response)

What is the Singer-Schacter theory of emotion?

Arousal, cognition, then conscious emotion

e.g. Oncoming car -> ANS arousal -> cognition -> conscious fear

(Reasoning is required for appraisal, before emotions can be identified)

What was Singer & Schacter's study that informed their theory of emotion?

Behavioral study in 1962

Participants given adrenaline (epinephrine) injection, then interacted w/ confederate, then rated their mood

IVs- 2 group conditions (Group 1 was informed, Group 2 was uninformed about the effects of injection); 2 script conditions (Confederate either had friendly or annoying script)

DV- self-reported emotion rating at the end

Hypothesis- cognitive appraisal will differ between the 2 groups (depending on their knowledge of injection effects)

Prediction- informed group would show lower emotion ratings (they should know in cognition step what led to ANS changes, being the injection rather than the confederate), uninformed group would show higher emotion ratings (would attribute feelings to confederate)

Results- Group 1 (informed) had lower emotion ratings; Group 2 (uninformed) thought they were experiencing much stronger emotions due to thinking the confederate made them feel this way

(hypothesis supported)

What is LeDoux's high/low road theory of emotion?

Arousal AND cognition (parallel process)

Theory of 2 parallel emotion systems- "high road" and "low road"

e.g. Oncoming car -> ANS arousal AND cognition (at once) -> conscious fear/behavioral response

High road = Cognition -> conscious fear; slow, sustained, controlled

Low road = ANS arousal -> behavioral response (fast, transient, automatic)

Key region for both systems = amygdala

How does the amygdala support both the high road and low road in LeDoux's theory?

Support for the high road (slow idea of cognition -> conscious fear): there are reciprocal connections between amygdala and "higher" cognitive regions like association cortex, PFC, etc.

Support for the low road (fast idea of ANS arousal -> behavioral response): amygdala receives direct sensory inputs and sends outputs to neuromodulatory systems