Lecture 11: Deja Vu

Chapter 9: Deja Vu

Deja Vu

• sensation of familiarity for something that you know to be unfamiliar

• episodes last 5-30 seconds

• subjective experience

• related positively to education and intelligence

Factors that impact Deja Vu….

• tired

• stressed

• intoxicated

• age (happens more in younger ppl

What are the types of Deja Vu?

• Associative

  • most common, happens when a new experience subconsciously resembles a past memory even if you don’t remember it

• Biological

  • liked to neurological conditions, occurs when theres abnormal electrical activity (hippocampus and temporal lobe)

Recollection

• remembering when or where an event took place

• e.g during the fall of 2019, I went to Disneyland with my family

• applied by bottom-up sensory-perceptual theorist

Familiarity

• thinking how familiar an event is to you

• e.g this bike looks very familiar, i feel like I have seen it a few weeks ago

Cognitive Theories of deja vu formation

• Dual-Processing

• Hologram Theory

• Divided Attention

Dual-Processing

• two cognitive processes that operate in synchrony become momentarily uncoordinated

  • e.g auditory and visual systems become uncoordinated

• Deja vu stems from familiarity

• e.g You walk into a café and hear a familiar song (auditory system), which triggers a feeling of familiarity, but since the café’s appearance (visual system) is new, the mismatch between the two sensory systems creates the sensation of déjà vu.

Hologram Theory

• memories are like holograms

  • only need one fragment to see the “full memory”

  • smaller the fragment = fuzzier the memory

    • error occurring in the past

• the brain is essentially replaying a stored memory, even if the details dont fully align

• e.g Walking down a street, you feel like you’ve been there before because your brain retrieves a fragment of a similar memory (like lamp posts or buildings) and reconstructs a sense of familiarity, even though the details don’t fully match.

Divided Attention

• The brain subliminally encodes an environment while we focus our attention on something else

  • when attention returns, we feel as if we have been here before

• occurs below conscious awareness

• brain processes info twice: once unconsciously, then consciously creating a false sense of familiarity

• e.g While texting and walking into a new café, you unconsciously take in the surroundings; when you look up and consciously notice the café, it feels familiar because your brain already processed it at a subconscious level.

Why was Deja Vu partly neglected?

its difficult to measure

Tulving (1985)

• modern view - subjective experience is important

  • cant recreate deja vu experience in a lab so they go off responses/behaviours

• plays a major role in memory

  • Classified memory based on experience

• suggest that without measuring experience you could not investigate cognition.

• His theory posits that memory retrieval is either self-knowing or not

  • this judgement was something that only the participant in an experiment could report.

  • episodic memories are self-knowing

Remembering

• signifies that you are retrieving something from your personal past, not daydreaming or inventing information.

• first-person experience

  • e.g i remember that word because I talked about my dog

• focused on contextual details

Knowing

• The feeling of knowing something tells you that information is stored and is readily available.

• its memory without self-experience

  • e.g I just know, I feel like I saw this word before

• focused on familiar sensations/feelings

Remember/Know Task

• it’s an experiential state

  • allows researchers to study our mental processing

• this is how researchers know when participants prove a remember or know the response

General Principles that underpin Research on Subjective Experiences

1. Subjective evaluations should relate to actual performance

2. subjective evaluations should relate to objective characteristics of stimuli

3. participants should be able to justify their responses

4. converging evidence from neuropsychology or neuroimaging

1. Subjective Evaluations should relate to actual performance

• feelings should relate to behaviour

• e.g if you feel that something has been very well learned, then your performance for that item should be high.

• People can predict how well they will perform or how well they have performed

  • suggesting that their subjective reports are indicative of some access to mental operations

2. subjective evaluations should relate to objective characteristics of stimuli

• different types of materials are remembered differently, and that these appear to be processed in different ways.

• e.g high- frequency words (such as ‘jacket’) and low-frequency words (such as ‘epaulette’) produce different levels of memory performance

• The low-frequency words are vivid and usually bizarre, they tend to generate rich, powerful memories

• whereas words like ‘jacket’ are difficult to differentiate, and tend to generate vague feelings.

3. participants should be able to justify their responses

• people’s justification of responses should relate to their experience and the way that they have responded to the test.

• e.g remember/know memory paradigm

• e.g ‘It’s vague – I think I saw it before’

• Justifications are particularly persuasive if people spontaneously justify their experience

  • or draw parallels between what you have produced in the laboratory and what they feel in daily life.

4. converging evidence from neuropsychology or neuroimaging

• If we are measuring a verifiable subjective process, we would hope that we could see it in the brain, or that it might break down systematically in brain damage.

• hippocampus - supports recollection (knowing)

• Perirhinal Cortex - supports familiarity

• This category is critical for deja vu

Why is category 4 critical for deja vu?

• If we can find out what brain region or mechanism might contribute to this strange subjective experience,

• we are closer to finding something objective and tangible and a means of categorizing subjective experience.

• its why investigating epilepsy where there are clear disruptions to brain function, and often in quite specific areas of the brain, has proved so insightful in a range of cognitive theories

Temporal Lobe

• processes emotion

• short-term memory

• language

• hearing etc

Epilepsy

• chronic neurological disorder that causes recurrent seizures

• Various factors cause these

  • genetic

  • brain injury

  • infection

• The brain consists of nerve cells that communicate through electrical signals

• Seizure: burst of abnormal electrical signals that interrupt the normal brain signals

• Spontaneous deja vu

Spontaneous Deja vu

• feeling of déjà vu that occurs without any identifiable trigger or external stimulus.

• Unlike déjà vu linked to specific sensory cues (like a familiar song or place),

  • spontaneous déjà vu seems to arise randomly, often without a clear connection to a past memory or experience.

• involves episodic details of before, during and after

Main 2 categories of epileptic seizures?

• Focal Seizure

• Generalized Seizure

Temporal Lobe Epilepsy

• beings in the temporal lobe (shocker)

• happens before onset of the seizure

• symptoms:

  • odd feelings such as joy, deja vu or fear

• Research can be done on them to understand self reports of Deja vu but further research is needed

Dreamy State

• refer to the ‘vague and yet exceedingly elaborate mental states’ that characterize certain seizures.

• often included vague sensations and feelings,

  • but notably scenes and experiences from the past, like flashbacks.

• e.g man who as part of his seizures detected strange smells, then began (uncontrollably) to think of ‘things from boyhood’s days’.

• exploration of dreamy states allowed neurological examination of consciousness, helped make links btwn brain function/physiology and subjective experience

Cognitive Feelings

They signal to the experient what processing is going on and how to interpret it.