Remembering Beliefs

1
Remembering Beliefs
Susannah Kate Devitt Rutgers Center for
Cognitive Science

• Introduction
• The experience of memory impacts our judgments of
  memory.
• Normal subjects can be quite reliable at
  distinguishing memories from imaginings. However,
  individuals are also susceptible to
• False Memories generated under suggestion from
  experimenters, therapists or self-generated in
  disorders such as schizophrenia.
• False memories are familiar and vivid, creating
  strong beliefs about their veracity.
• Functional amnesias found multiple personality
  disorder, dissociative fugue or post-traumatic
  stress disordere.g. rape victims.
• Functional amnesia patients respond to stimuli
  associated with an instigating event without
  familiarity or sense of connection.
• QUESTION Is subjective experience sufficiently
  fallible to render it an unjustified source of
  evidence about the origin of our mental states?

Bayesian Rationality Bayesian rationality
provides a defense of source-monitoring. The
congruence between independently generated
beliefs can raise the likelihood of a memory
analogously to the way that agreement of
independently given testimonies can convince us
that what is being testified is true. Caveat
One must already have a degree of belief in the
memory before coherence can play a role. Thus not
useful in functional amnesia where the subject
believes that their experiences are not in any
way related to memory. Bayes theorem Common
phenomena are more probable, so each instance is
less useful is as evidence in evaluating a
hypothesis i.e., common signals provide less
information.

• Summary
• Implicit memory functions without necessarily
  any beliefs or qualia.
• Episodic memory functions with mnemic qualia and
  belief that it is a memory.
• The coherence and detail of mnemic qualia affect
  belief.
• A Bayesian model of memory provides a plausible
  mechanism of memory belief evaluation.
• Source-monitoring errors are explained within
  the Bayesian model.

• Remembering Requires Belief
• Memory of past sensations seems only possible by
  means of present imagesHowever images without
  beliefs are insufficient to constitute memory.
  Bertrand Russell, Analysis of Mind IX.
• Having qualia and the right causal connection to
  an event will not ground an experience as an
  episodic memory.
• E.g. Introspecting images of our keys is not
  sufficient to recollect where we left them.
• Believing that x has occurred is necessary for
  recollecting x.

E.g., an individual who consistently experiences
strong mental imagery whether dreaming, imagining
or remembering should not take the existence of a
mental image to be much evidence of the origin of
a thought, where as their recollection of a smell
or texture could trigger a dramatic and justified
belief revision.
Remembering

• Remembering Does Not Require Belief
• Implicit memory systems, both embodied and
  representational can operate without
  beliefalthough implicit beliefs can occur.
• Philosophical example Imagine a painter who,
  when asked to create an imaginary scene, ends up
  painting a detailed picture of a farmyard she
  visited as a young girlas confirmed by her
  parents.
• Believing x has occurred is not necessary for
  remembering x

• Q. Are the faculties of the mind sufficiently
  independent to count as separate witnesses?
• Individuals differ in their reliance on different
  modalities, e.g. mental imagery or auditory
  phenomenology.
• Individuals have inductive evidence for how each
  modality is likely to activate during remembering
  or imagining.
• Individuals use this information to adjust the
  evidential role each modality plays in memory
  assessment.

• Mnemic Qualia
• Mnemic qualia is the qualitative aspect of
  remembering. E.g.
• Implicit memory Sense of familiarity when
  riding a bicycle.
• Explicit memory Vivid recollection of events
  from 9-11-01.
• Hume (1777) hypothesized that because true
  memories reliably generate more detailed and
  coherent qualia than imaginings, we must use this
  qualitative feedback to evaluate the origins of
  our mental state.
• Critics have noted that qualia can trick ustoo
  much focus on how memories feel, rather than
  whether it is rational to believe them, leads to
  false belief.
• How should mnemic qualia affect our beliefs about
  memory?

although the painter sincerely believes that
her work is purely imaginary, and represents no
real scene, the amazed observers have all the
evidence needed to establish that in fact she is
remembering a scene from childhood. Martin
Deutscher, p. 168.

• Q. Is coherence manufactured to conform to
  existing beliefs?
• Individual differences in imaginative capacity
  affect subjects ability to manufacture coherence
  at the expense of veracity.
• E.g. autistic spectrum disorder subjects are
  less susceptible to false memories, where as
  fantasy-prone subjects frequently experience
  source-monitoring difficulties.
• Individuals with strong imaginations should
  place less evidential weight on mnemic qualia
  when remembering.

Source Monitoring Source monitoring an
inferential process to identify the source of
mental states via their qualitative features and
coherence with relevant beliefs (Johnson et. al.
1993). The more qualitative features
cohere, the greater the likelihood an experience
is a memory and we revise our beliefs
accordingly.
Mnemic Blindsight Blindsight is a phenomenon
where patients with partial blindness are able to
respond accurately to visual cues better than
chance, even without visual phenomenology
(Stoerig Cowey, 1997). Mnemic blindsight
occurs when a person utilizes remembered
information without awareness or belief that it
is remembered. Mnemic blindsight reported
for multiple personality disorders, dissociative
fugue and post-traumatic stress disorder subjects
such as rape victims (Kihlstrom Schacter,
2000).
Bibliography Johnson, M. K., Hashtroudi, S.,
Lindsay, D. S. (1993). Source monitoring.
Psychological Bulletin, 114, 3-28. Kihlstrom,
J.F. Schacter, D.L. (2000). Functional amnesia.
In L. Cermak (ed), Handbook of Neuropsychology,
2nd edn, Vol. 2. Amsterdam Elsevier
Science. Hume. D. (1777) Enquiry Concerning Human
Understanding. Lyon, L.S. (1985). Facilitating
telephone number recall in a case of psychogenic
amnesia. Journal Behavioral Therapy and
Experimental Psychiatry. 16. 147-149. Martin,
C.B., Deutscher, M. (1966). Remembering
Philosophical Review, 75. 161-96. Oaksford, M.
Chater, N. (2007) Bayesian Rationality. New York
OUP. Olsson, E.J. Shogenji, T. (2004) Can we
trust our memories? C.I. Lewiss Coherence
Argument. Synthese, 142. 21-41. Stoerig, P.
Cowey, A. (1997). "Blindsight in man and monkey".
Brain 120 535559
Lyon (1985) describes a patient who was unable to
explicitly retrieve any autobiographical
information, yet dialed their mothers phone
number when asked to randomly dial numbers.
Email skdevitt_at_gmail.com I would like to thank
Rutgers Center for Cognitive Science and Rutgers
Philosophy for their financial support of this
poster.