TJ&DM Flashcards
‘Gastrophysics’ borrowed its name from…
Psychophysics - the field that investigates the relationship between objective qualities of stimuli and experienced sensory qualities
Preconceived perceptions (gastrophysics)
Pre-conceived perceptions can enhance the experience of food, but it can backfire if it doesn’t meet expectations
Taste (gastrophysics)
○ Basic tastes come from the tongue: sweet, sour, salty, bitter (maybe umami = delicious?)
○ What about fruity, smoky, herbal, burnt, and all the many others?
○ These are flavours, and they emerge when smell is added
○ The classical tongue mapping is probably not true - there are relative differences, but great variability between people
Oral referral
Smell adds to the taste experience, but we do not realise this but “project” the experience to the tongue
- orthonasal
- retronasal
Orthonasal
Sniffing external aromas
Retronasal
Aromatic odour is received through the back of the mouth into the back of the nose during food consumption
- this is where the rich perception of aroma comes from
Key Gastrophysics message
® There are still individual differences and some people will prefer black and some will prefer white
® But when there appears to be a generalised trend that replicates, it can be useful in the real world
Is the science of gastrophysics sound?
Pay attention to the methods and statistics:
§ What kind of statistical tests are used, and are they appropriate?
§ How many tests are conducted, and do the authors control for multiple comparisons?
§ How many participants were tested, and what is the reported effect size (if any is reported)?
§ Do the results replicate across studies?
What other factors could have biased participants (and the results)?
Making decisions after consuming (Bode)
® Idea that if you are waiting for a large reward you will be impatient and think it is 2 secs quicker
Actually found that after a large reward, the estimate is longer but after a small reward it is shorter
□ Turns out high calorie consumption actually led to less patience, which is not what they expected
Anxiety vs Fear response
They share many common physiological features, but they can be differentiated:
Fear responses are elicited by specific stimuli and tend to be short lived
Fear responses decrease when a threat has been removed or dissipated
Anxiety may be experienced in the absence of a direct physical threat and typically persist over a longer period of time
Extinction of a conditioned fear response
e.g. presenting the tone repeatedly without the shock, resulting a gradual decrease in the conditioned fear response
Extinction is the basis for graded desensitisation training in psychological practice
Systematic desensitisation
Developed in the 1950s by Dr Joseph Wolpe
attempts to replace an anxiety or fear response with a relaxation response through a classical conditioning procedure
You gradually associate, through repeated pairing, a fear-arousing stimulus with a state of relaxation, in a series of graded steps
Really important that you replace the anxiety or fear with relaxation response before upping the stimulus
3 ways conditioned fear returns
§ After the passage of time (Spontaneous recovery)
§ Changes in context (Renewal effect)
§ Stress (Reinstatement effect) - one of the more common ones
interpreted as evidence that the original ‘fear memory’ is not deleted, or erased, but rather inhibited during the extinction phase of conditioning experiments
Fear conditioning neural network structures
Include the amygdala, hippocampus, ventromedial PFC, dorsolateral PFC, and striatum
Cognitive regulation (neurology and 2 strategies)
the dorsolateral prefrontal cortex (dlPFC) regulates fear expression through projections to the vmPFC, which in turn inhibits amygdala activity
Strategies include:
§ Reinterpret the significance of an event (cognitive reappraisal)
§ Focus attention on the less fearful aspects of a situation (selective attention)
Active coping (basic idea)
argued to be the most commonly used ‘untaught’ method we use to regulate our emotions
strategies involve an awareness of the stressor, followed by attempts to reduce the negative outcome
Learning an action to avoid a fearful event or diminish the fear response
Active coping (neurology)
○ During active coping, info from the LA (lateral nucleus) is routed not to the CE (central amygdala), which drives fear expression, but to the B (basal amygdala), which in turn projects to the striatum. The striatum is thought to reinforce instrumental action taken during escape- from- fear or avoidance learning
Reconsolidation period
○ Diminishes conditioned fear expression through alteration of the original CS-US association stored in the LA
Linked to the idea that immediately after learning there is a period of time where a memory is fragile, less permanent
○ During the consolidation period, you actively seek to disrupt the formation of the memory
○ Or, if you are past the consolidation period, you look to modify or inhibit, but not eliminate, the memory, by actively retrieving the memory
○ The act or retrieval makes the underlying memory trace fragile again, called the reconsolidation period
- potentially allowing you to block the memory completely
Kindt et al. (2009), Schiller et al. (2010) and Debiec and LeDoux (2004)
were the first to show that in humans you could use propranolol to block the return of fear
Still not clear what the mechanism for propranolol’s effects are
Anxiety and Fear
Several prominent theories of Anxiety Disorder propose that dysregulation of the neurocircuitry of conditioned fear may be central to the disorder
trait anxiety is associated with heightened amygdala activation and elevated fear expression
Anxiety also impairs extinction learning and retention, as well as the regulation of emotional responses via cognitive strategies
○ These deficits appear to stem from impairments in the regulation by prefrontal cortex of the amygdala ○ For example, anxious patients exhibit reduced prefrontal activation during or before fear extinction, and require heightened prefrontal recruitment to successfully reduce negative emotion with cognitive reappraisal
Cognitive effects of Anxiety (info processing biases)
two key cognitive information processing biases:
- A bias to attend toward threat-related information
- A bias toward negative interpretation of ambiguous stimuli
Anxiety and Attention Threat Study (ambiguous faces + homphones)
For stimuli with more than one potential interpretation, people with anxiety have a tendency toward a more negative perception
§ Ambiguous facial expressions (Richards et al., 2002)
§ Face-voice pairings
§ Verbal homophones
□ Die or Dye
When evaluating the probability of future life events, individuals with anxiety will judge the probability of negative outcomes as far more likely than non-anxious controls
Anxiety and economic decision making
hyperactivity of the amygdala, while attending to, evaluating or anticipating negative stimuli, contributes to heightened cognitive and affective responses to a potential threat stimuli
Prefrontally mediated cognitive and affective regulation processes also appear to be impaired in anxiety, reducing the ability to modulate these pre-existing tendencies
Uncertainty
Across species, stimuli that are unpredictable will elicit greater anxiety
people with anxiety will show threat-related information processing biases that alter their decision making
Humans as a general trait will be risk averse
For all, the amount of attention given to the aversive choice option predicts the likelihood of avoiding that option
Importantly, when the decision paradigm requires the anxious participant to make a choice for another person, they are less risk averse