Category: cognitive science

Category specific semantic deficits: implications for structure of conceptual knowledge

Category specific semantic deficits: implications for structure of conceptual knowledge

images (1)Cognitive psychology is well-known for attempting to use individual cognitive – and SPECIFIC – failures as catalysts for larger discussions about the structure of processes critical to human rational thinking.

Attached is a power point presentation I created as an undergraduate after reviewing numerous case studies. It summarizes my own commentary re: both the case studies per se and the theoretical stakes of this problem-set.

Category-Specific Deficits 2

Continue reading “Category specific semantic deficits: implications for structure of conceptual knowledge”

Possible evidence for the linguistic relativity hypothesis

I’ve been researching–or attempting to research–any academic work that’s been done on semantic representation (i.e. intensions/extensions) AND linguistic relativity.  My search so far has proved unsuccessful.

Oppositely, I’ve found a wealth of information concerning the empirical justification for linguistic relativity.  Undressmerobot.com offers an informative review of the issues concerning linguistic relativity, but mostly from the standpoint of social psychology.

That said, I find this evidence particularly favorable for linguistic relativity:

One of the most telling tests was one that dealt with the duplication of lines on a piece of paper. Gordon drew single and multiple lines on a piece of paper and asked the Pirahã members to copy those lines. For one, two, and three lines, the Pirahã had no difficulty completing the task. As the number of lines increased, the discrepancy between the number of lines and number of copied lines also increased. For instance, many only reproduced three lines when shown four (Holden).

Of course, in order to justify the strongest version of the hypothesis, the researchers (Holden, and I’m not sure who else) would have to show that the task itself was completely non-linguistic.  Surely we think of simple copying tasks as non-linguistic, but the description above is obviously a summary and therefore incomplete.

Nevertheless, interesting evidence.

Response to de Villiers’ Language for Thought: Coming to Understand False Belief

The following is a short response I wrote to de Villiers and de Villiers’ Language for Thought: Coming to Understand False Belief. (de Villiers, J.G., and P. A. de Villiers. Language for Thought: coming to understand False Beliefs. Chapter prepared for Whither Whorf? (in press)) You can view a version of it here, although I’m not sure it is the final version.

 

de Villiers and de Villiers, in Language for Thought, articulate the view that language is prerequisite to thought and not merely an effect of it. They focus exclusively on the issue of false belief and our ability to reason and form explanations about them. Specifically, the acquisition of language is a necessary condition for the ability to describe not the content of false beliefs (others’ false beliefs).

 

De Villiers and de Villiers offset their hypothesis that language is prerequisite for thought with the following dilemma: any appropriate experimental design results in either triviality or incoherence, depending on the criterion for acceptable results and/or the encouraging of participants (children, in this case) to use intentional language capable of describing false beliefs. (351) To resolve this tension, de Villieres and de Villiers propose two solutions:

 

1) Select tasks that do not require the explicit use of “linguistic complements”—the propositional content of an intentional expression—and thus accept responses that fail to denote ‘what about the belief is false’.

2) (a). Select tasks that require very little regarding the understanding of linguistic complements, so in effect children would merely be required to imitate (i.e. “repeat”)—and not grasp–the false intensional expressions they hear. (b) Inquire as to whether children have “mastered complements with nonmental verbs, such as verbs of communication that require precisely the same complement structures syntactically and semantically as mental verbs, but with none of the reference to invisible mental events.” (352)

 

I want to focus on the latter half of the second proposed solution. The authors seem to imply a sort of dualism concerning mental predicates such that so-called folk psychological states—i.e., intensional verbs—necessarily denote a state with content that cannot be confirmed in an empirical sense; hence de Villiers and de Villiers use of “invisible mental events”. This is the hallmark of 20th century theories of mental content-intentional states like to believe, to think, to remember, and to wish, are understood as states having objects that do not refer to anything physical and/or confirmable; at least not in the sense that “The ball is front of the desk” is.

 

Without getting into the matter of how best to think about the meaning of such expressions, it should be acknowledged that anyone, let alone children, need not be using intensional verbs in such a Cartesian way (‘Cartesian’ because such verbs are taken to denote mental, ‘invisible’ things). In many circumstances one might be disposed to say that his or her use of the predicate ‘to think that’ ought not be thought of as denoting a mental state but rather as merely ‘directing the audiences’ attention’. Here the meaning of intensional verbs becomes less mysterious and more socially embedded. Thus, the use of intensional verbs might be merely for emphasizing what follows the intentional verb. Compare “I think that the Patriots are too good” with “The Patriots are too good”: with regard to syntax alone, the latter expression would not fall under de Villiers and de Villiers’ notion of complement structures since it lacks an intensional verb conjoined with a corresponding ‘mental’ or representational content. In a room of crowded people, someone who uses ‘I think’ or ‘I wish’ might be more realistically be thought of as an attention-grabber. I suppose the use of intensional verbs might be looked at in both ways simultaneously, and certainly I don’t think that the two are incompatible.

 

That said, if it’s the case that, on many occasions, an individual might not use intensional verbs in the strict sense that the authors require in order to resolve the alleged dilemma, then they need to rethink just how pressing the tension is in the first place.

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Note: After reviewing this rather hasty response, I need to qualify my critique, to an extent. Yes, the description of intensional predicates as ‘invisible’ sounds or seems to imply a sort of Cartesian dualism-the fact is, the authors do not require a separate ontological category of “mental substance”, so its not entirely (that is, ontologically) dualistic.

Quine’s weak Whorfian hypothesis?

I am continuing to notice both implicit and explicit parallels between two different discourses: on the one hand, the philosophy of language/mind, and on the other, cognitive and psycholinguistics. Its eye-opening: I hadn’t been aware how influential many of the anglo-american philosophers I am familiar with were to other, non-philosophical discourses.

F. Xu, in The role of language in acquiring object kind concepts in infancy (Cognition, 85), showcases Quine’s influence on “theories of conceptual development in which language plays a crucial role.” (Xu, 224)  Quine’s view may be seen as a weaker Whorfian hypothesis to the extent that it holds cross-linguistic differences as corresponding to cognitive differences between groups. More importantly, apparently, is Quine’s regard to the ontological effect of such cross-linguistic differences.

“Quine…considered how language may be used to build our ontology.  Most widely discussed is the case of the conceptual distinction between objects and substances from the linguistic distinction of count/mass syntax.  Quine proposed that the infant’s world is profoundly different from ours for lack of representations of enduring objects, and that it is by learning the count/mass syntax of a natural language, e.g. English, that the infant is able to “boot-strap” herself into a more adult-like conceptual scheme.  On this view, [call what follows p] cross-linguistic differences result in profound conceptual differences in adults; e.g. speakers of Japanese, which lacks the count/mass distinction, would not represent the ontological distinction between individuated entities, such as objects, and non-individuated entities, such as substances. Furthermore, [call what follows q]children learning different languages would follow rather different developmental trajectories.” (Xu, 224)

Oddly, Xu goes on to imply that Quine’s view can be distinguished further: “Empirical investigations of this issue have found that the strong version of this view is wrong: even English-speaking children who have not mastered the count/mass syntax already differentiate objects from substances in extending word meanings.” (Xu, 224)

To be honest, I’m not entirely familiar with Quine’s theory of cognitive development.   I’m not entirely sure, either, of what the “strong” version of this account is–though I suspect it is the idea that “children learning different languages would follow rather different developmental trajectories.” (Xu, 224)

To review, the difference between the strong and weak Whorfian claim is allegedly that the former supports a “linguistic differences correspond to cognitive, non-linguistic differences in thought between groups” line of thought while the latter supports the lesser claim that certain KINDS of cognition, a “thinking for speaking” kind, might be influenced by linguistic effects.

The alleged distinction in Quine’s theory of cognitive development (i.e. that BOTH p and q) doesn’t parallel the strong/weak distinction in the context of Whorfian claims.  Unless someone else can offer another way to read Xu’s interpretation of Quine’s view, that is.

Problems with testing the ‘linguistic relativity’ position

I’m currently enrolled in a course that has focused mostly on the linguistic relativity position as it exists in contemporary cognitive psychology (and to some extent, anthropology).

In a very basic sense, the linguistic relativity position says that the language a person uses determines how he or she thinks about the world in the sense that users of distinct linguistic communities actually encode (i.e. represent) the world (or an aspect of it) quite differently.

There are a number of problems characteristically cited in contemporary discussions that I’d like to review.  I’ll present these simply as obstacles to an objective treatment of this view.

  • Significance of the way the instructions of a task are presented (especially relevant in bilingual and/or cross-linguistic experimental designs)
  • Domain vs. Structural-centered approaches
  • Cultural vs. Linguistic effects on cognition
  • Population representation: the samples of these studies rarely (if ever) can be said to be representative of the “linguistic community” that they are purportedly members of
  • Insufficient description and/or knowledge of cultural differences within a particular “linguistic community”

Another I’d like to add to the list is:

  • Conflation and/or imprecise use of the term “language” and/or “linguistic community”

The latter could be rephrased as “issues concerning the projectability (in the sense that Nelson Goodman attributes to that term) of ‘linguistic effects’

To put it in a much better way: even if an experiment (and its interpretation) purport and do a good job of showing a correspondence between a linguistic difference and a cognitive difference between two communities, its uncertain whether the conclusion(s) is projectible to “language in general”–or, to emulate Heidegger’s treatment of ‘being vs. Being’–Language.

So for instance, let’s say that users of Language A actually do differ in their experience of ‘space” (i.e. in their spatial cognition) as compared to users of Language B, does it then follow that

  1. “linguistic relativity is true” because it was shown that members of one linguistic community manifested distinct cognitive patterns as compared to the cognitive patterns manifest for members of another linguistic community….OR
  2. “linguistic relativity is true” because Language (i.e. “language itself”) determines the cognitive differences observed in different linguistic communities (that is, “different linguistic communities IN GENERAL” and not merely “differences among particular linguistic communities”)

Long story short is that depending on how a conclusion regarding the relationship between “language users” and “thought” (i.e. cognition of a nonlinguistic type) is projected, you’ll see very different takes on the “stakes” of the claim.  In the first case the cognitive difference is due to language-effects between one particular linguistic community and another particular linguistic community.  In the second case, the cognitive difference (i.e. the difference in thought) is taken to indicate a general effect of language itself, that is, Language…otherwise known as “the capacity for language”.

In a very short time observed cognitive differences between distinct linguistic communities becomes explainable via recourse to “the capacity for language”–a description in close proximity to something an advocate of Chomsky’s positions might say.  The irony is, of course, that proponents of the linguistic relativity position are OPPOSED to Chomsky’s program, to the whole edifice upon which the “universal grammar” conception is built.

Implications of Memory Pathology in Schizophrenia

I’m going to change it up with a short paper I wrote in my cognitive psychology class on schizophrenia.  I chose this paper because it discusses theoretical implications for any explanation of the cognitive aspects to schizophrenia via an analysis of three case studies involving deficits and/or surpluses in patients with schizophrenia.  Unfortunately, as the class was a couple of years ago I don’t presently have the book that contained the case studies I was basing the paper on, so I can’t provide references to the case studies other than by the patients name (a characteristic practice in the field).  So if anyone knows the exact case study name(s) and/or the scientists that were credited for them, let me know.

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Schizophrenia is frequently complicated by a decline in general intelligence.  Underlying the decline in intellectual capacity are several neuropsychological deficits that are thought to contribute. Deficits in memory and executive functioning are frequently witnessed in these cases, but their relationship to the general decline is not so clear.  The implications of the three case studies to be assessed in this article conjointly challenge the contemporary idea that specific neuropsychological defects in memory and executive function are part of the larger pattern of general intellectual deterioration in patients with schizophrenia.

The patient TC represents the typical schizophrenia of impaired memory and impaired frontal lobe functionality as each part of the larger pattern of general intellectual decline.  His poor performance on virtually all long term memory tests justifies the claim that his long term memory is extremely impaired.  Also consistent with the conventional theory is manifestly impaired frontal lobe functionality; in the Wisconsin Card Sorting Task he displayed an inability to switch rules even when asked.  Language functionality in TC is a bit of a different story: he has trouble understanding semantics but can understand grammar.  Given his rather significant decline in general IQ (from 113 to 68) perhaps it is the case that semantic memory is more central to the pattern of intellectual decline but memory for grammar is somewhat of an independent module.  This may become even more clear when we compare TC with another case study of the patient DS.

There are striking similarities because DS and TC, however there are also significant differences.  Both DS and TC exhibited motivation with respect to the cognitive testing; this suggests that in some ways the extent and pattern of their cognitive disabilities spared them important social skills like motivation and the ability to cooperate.  This is somewhat of an anomaly; in most schizophrenics there is a marked decline in cooperation and motivation.  Perhaps in most other cases where patients are uncooperative and unmotivated, we can infer that schizophrenia is only indirectly linked with these social deficits insofar as, perhaps, it caused the social ridicule in various environments because proper action was taken, et cetera.  Thus, cognitive deficits of schizophrenia may be functionally distinct from the individual’s level of cooperation and motivation.  Like TC, DS exhibits a significant deficit in long-term memory, with a spared short-term memory.  However, the manifestation of DS’s compromised long-term memory is comparatively complex; procedural memory is spared, while semantic, autobiographical and recognition are all in the severely impaired range.  Also different from TC was DS’s comparatively decreased decline in general IQ (115 to 101) and his normal functioning of the frontal lobes and executive processes.  Thus, it seems DS’s neuropsychological deficits are relatively distinct from the general deterioration of intellectual capability.  DS’s relatively stable IQ level may be attributable to his intact executive functioning, or it also may be attributed to his academic background prior to the onset of illness: that he can still understand languages he learned prior to onset suggests he has retained a significant portion of his intellect.  Perhaps too, as we compare TC with DS, we may suggest that the general deterioration of intellect in schizophrenia is at least lessened if the individual had a rather extensive and sophisticated education, as is the case with DS.

EN’s case is a bit uncharacteristic of schizophrenia: that she “appears superficially well and has managed to find part-time work” suggests that, at least with respect to her ability to find work, her illness has not completely devastated motivation.  The delusional aspect of her schizophrenia is manifestly the most important: in an interview she actually lapsed into delusional confabulation, whereby the patient produces new delusions and delusional memories apparently spontaneously.  This is very different from the memory impairment of both DS and TC; in her case it suggests that the general pattern of intellectual impairment is functionally irrelevant to memory; her memory impairment thus seems independent of any other further association.  While DS’s memory impairment is also separate from executive functionality, EN’s manifestation of memory impairment is markedly different: EN’s memory deficits manifest only in her confabulation.  While DS suffers from memory impairment, we may say that EN suffers not from impairment, but from “deranged and corrupted” memory.  Additionally, an inference we can draw is that her memory impairment as manifested in delusional confabulation seems functionally linked with her abnormality in autobiographical memory.  This is interesting because DS also shows some problems in autobiographical memory, but in his case does not seem to be casually linked with the onset of delusional confabulations.

In all three cases we see the presence of memory impairment; however only one case supports the idea that memory impairment is associated with the larger pattern of intellectual decline.  There is also an important qualitative distinction to make: it seems that delusional confabulation is qualitatively different from the long-term memory impairment of DS and TC.  It is not enough to merely say that EN’s memory is not functioning with the same degree of accuracy as the normal subject; we must say that in fact her memory is functioning on a completely different level than the normal subject.  Lastly, we may conclude that it is not at all law-like that the general intellectual impairment and the specific neuropsychological deficits in schizophrenia are directly linked with the positive and negative symptoms of the disorder.