School of Psychology, Birkbeck College

Course PSYC044U (Psychobiology II.) WEEK 10
April 26th 2007

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gifThis is just the first 6 pages of the longer paper handout. Web versions of the other pages in the paper handout are accessible from the side index. If you need to print out the handout, then all the pages are in this 'pdf' file, but this is quite large and may be difficult to download over a telephone modem.

 

PRIMATE COGNITION 1: GENERAL ISSUES AND ATTEMPTS AT ‘LANGUAGE’ TRAINING

[top of page 1 of handout]
Essay (no 8 on the March 15th list)


“Apes cannot be taught language, but there is evidence that they have special abilities in the areas of social learning, imitation, and self- recognition.” Discuss.

 

 

[top of page 1 of handout]
Notes (see also the Easter Handout for Summer-Term Lectures)



A quotation —

“A third hypothesis proposes that there are, in fact, neither quantitative nor qualitative differences among the intellects of non-human vertebrates. It is argued that this null hypothesis is currently to be preferred, and that man's intellectual superiority may be due solely to our possession of a species -specific language- acquisition device” (Macphail, 1985; p.37; see also Macphail, 1996 and Macphail and Bolhuis, 2001).

Notes

  • Macphail is an example of those who disagree that primates (other than humans) have more than co-incidental cognitive advantages over other species. He supports a ‘null- hypothesis’ of equal intelligence (assessed in terms of associative learning) across all vertebrate species. Others such as Herman (see Shyan and Herman, 1987) would suggest that there are species differences in cognitive ability, but that certain non- primate species (dolphins, or other large-brained mammals) demonstrate primate levels of performance on complex tasks. Macphail (1985, 1998) and Heyes (1998) take the view that there essentially no differences betewen the cognitive capacities of different vertebrates species, as the above quotation suggests. Slotnick (2001) has argued that small-brained animals are often as good or better that large-brained animals at solving complex associative problems and Giurfa et al. (2001) have data suggesting that honey bees are able to learn “sameness” and “difference” concepts which had previously thought to be a primate speciality (e.g. Thompson and Oden, 2000)

  • An opposite view is that because primates are biologically more similar to people than other species, cognitive processes in primates (especially in our closest living relatives, the great apes) will be noticeably human-like, and distinguishable, quantitatively or quantitatively, from those of non-primate species. It is clearly necessary to assess the behavioural evidence very carefully in order to evaluate the soundness of this assumption. Slotnick (2001) has argued that small-brained animals are often as good or better that large-brained animals at solving complex associative problems and Giurfa et al. (2001) have data suggesting that honey bees are able to learn “sameness” and “difference” concepts which had previously thought to be a primate speciality (e.g. Thompson and Oden, 2000).


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    [bottom of page 1 of handout — with added bullet points]
  • An extreme case of the notion of primate cognitive superiority was the expectation that, with a sufficiently favorable training environment, infant apes might develop linguistic competence (e.g. Premack, 1976). Studies which attempted to train apes in language-like skills are reviewed in Walker (1985) and Walker (1987). (See page 3 for a summary table).
  • There is now a general consensus that some or other of the cognitive processes necessary for linguistic communication is innately and exclusively human (Hauser et al., 2002; Elman, 2005; Rivas, 2005; Pinker & Jackendoff, 2005).
  • In particular Premack (1986) said he could find no trace of properly linguistic abilities in chimpanzees after many years of attempting to, and concluded that the human species possesses a number of ‘hard-wired’ cognitive specializations, including that for recursive syntax.
  • However Premack (1986) continued to believe that non-human primate cognition is distinctive. In 1983 he proposed that only primates have an ‘abstract code’ for higher-order representations of object properties. In 1986 Premack suggested that primates were distinctive in the understanding of the semantic categories of the agent, recipient and patient of an action.
  • (See page 7 for a definition of these terms, and Crockford et al., 2004, Pika & Mitani, 2006, Wich & de Vries, 2006 and Hopkins et al., 2007 for other primate abilities with some relation to verbal and gestural communication.)

  • Although evidence for language-like communication in apes remains weak (despite Savage-Rumbaugh et al 1986 and Greenfield and Savage-Rumbaugh, 1993; Bodamer and Gardner, 2002; Jensvold and Gardner, 2000; see Rivas, 2005), experimental studies of primate cognition have implied that apes, and to a lesser extent, monkeys, are at least quantitatively superior to other species at various kinds of reasoning task (e.g. Gillan et al 1981; Menzel et al 1985; Boysen and Himes, 1999; Call, 2001; Tomassello, 2000; Boesch, 2002; Brauer et al., 2005; Melis et al., 2006: see also week 11).

  • Many authors going back to Jolly (1966) and Humphrey (1976) have supposed that primate intelligence is related to the complexity of primate social interactions. Recent examples include Crockford et al., (2004), Perry et al., (2004), Tomasello et al. (2005) and Pika and Mitani (2006). “Theory of Mind” hypotheses suppose that only some species have a functional concept of “self” (Gallup, 1970) or that only particular species (usually only the great apes) are able to make inferences or assumptions about the goals and intentions of conspecifics or human experimenters (Premack and Woodruff, 1978; Whiten and Byrne, 1997). This has recently attract extra interest because of the hypothesis that human autism is characterised by a lack of this capacity (e.g. Leslie, 1987). The social cognitive features of “shared-reference” (or “shared-attention”) and “proto-declarative” communicative acts have been proposed as important pre-conditions both for the development of a “theory of mind” and for the development of human language (Baron-Cohen, 1992; Savage-Rumbaugh et al, 1983; Tomasello, 2000; Suddendorf and Whiten, 2001; Elman, 2005: see Week 11)



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Further notes on species differences in cognition


1. Global versus local adaptations (Davey, 1989)

Macphail’s “Null hypothesis” corresponds to an emphasis on “global adaptations” (see sheet 5 of the week 3 handout). It is certainly the case that behavioural processes such as habituation are very widespread across species, but there is also evidence for species specific specializations such as visual recognition and memory for food locations as discussed in week 8 and week 9.

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2. The issue of brain size (page 9 in Pearce, 1997)

There are extremely large differences between species both in absolute size of the brain, and in the size of the brain in relation to body-weight. Although the relation between brain-size and brain function is to some extent indirect, one of the reasons for assuming that primate cognitive abilities may differ from those of the average mammal is that primates in general have above-average brain weights for their body size. (see page 8 of handout for replotted data and Ponting & Jackson, 2005, Evans et al., 2006 and Tang, 2006 for recent studies of the genetic mechanisms behind the increases in brain size in primates and in humans in particular.)

3. Specializations in brain function.

Most primate species share with humans the specialization in foveal colour vision, which is not used by other mammals, and elaborate social interactions exhibited over a long life-span. In terms of both ecological and anatomical specializations therefore, we would expect to find something in common between human cognition and cognition in primates (e.g. Barton, 1998; Regan et al., 2002). There is increasing evidence, in part due to brain-imaging studies in humans, that there is detailed correspondence between localization of brain function in humans and other primates (e.g. Ungerlieder, et al, 1998; Courtney et al, 1998; Rizzolati et al, 1996; Cantelupo and Hopkins, 2001; Miller et al., 2002; Semendeferi et al., 2002; Bush and Allman, 2004; Schenker et al., 2005; Sherwood et al., 2006; Tsao et al., 2006).

However, a recently emerging field of research is the genetic and neural aspects of brain development and function which are uniquely human (Enard et al., 2002a and 2002b; Elson et al., 2001; Buxhoeveden et al., 2001; Rilling and Seligman, 2002; Preuss et al., 2004; Pollard et al., 2006)



[page 3 of handout]
Summary of Attempts at “Language” Training
References Name(s) of animals Mode of Communication Training
Kellogg and Kellogg (1933)GuaVocalHome rearing
Hayes and Hayes (e.g. 1951) Vicki Vocal Home rearing, moulding of lip position
Gardner and Gardner (e.g. 1969). Jensvold & Gardner (2000); Bodamer & Gardner (2002) Washoe (& others) American Sign Language (ASL) Semi Home rearing, no vocalization, imitation and sign moulding, reward.
Terrace et al (1979) Nim Chimsky ASL 'Home rearing', many trainers, imitation.
Muncer & Etlinger (1981) Jane ASL (limited vocabulary of objects, prepositions and conjunctions. 1 year of lab style reward training, then 'Critical trials' in novel tests.
Premack (1970-1986) Sarah (& others) Plastic tokens as symbols for objects, verbs, and abstract categories. Lab style sessions, examples and initial reward. Attempts to control for experimenter effects.
Savage-Rumbaugh et al (1973-1985) Austin and Sherman 'Lexigrams' (Arbitrary visual symbols on a keyboard and computer-controlled display. Examples, and initially specific reward training, (later more general encouragement)
Savage-Rumbaugh et al (1986 and later years) Greenfield and Savage-Rumbaugh (1990, 1993) Kanzi (& Mulika) Lexigrams on portable keyboard & ASL & spoken English Initially imitation of natural mother: very rich environment but no formal training and no food reward; learning during ‘informal’ daily activities.

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Main Sources — Primate Cognition

Roberts, W.A (1998) Principles of Animal Cognition. Boston: McGraw-Hill. Chapter 12 "Primate Cognition".(1 copy on short loan at BK; 4 loan copies)

Walker, S.F. (1985). Animal Thought. Routledge & Kegan Paul: London pp 339-388

Walker, S.F. (1987b). Animal Learning. Routledge & Kegan Paul: London. pp. 332-357.

Further Reading — Primate Cognition

Boysen, ST and Himes, GT (1999) Current issues and emerging theories in animal cognition. Annual Review of Psychology, Vol.50, Pp.683-705.

www. version of this paper (If at BK or using BK dial-up software)

Heyes, C.M. (1998) Theory of mind in nonhuman primates. Behavioural and Brain Sciences, 21, 108-148.

www.pdf version of this paper(v.long (If at BK or using BK dial-up software) Preprint of just the paper

Macphail, EM (1996) Cognitive function in mammals - the evolutionary perspective . Cognitive Brain Research, Vol.3, No.3-4, Pp.279-290.

Pearce J.M. (1997) Animal Learning and Cognition 2nd Edition. Hove: Psychology Press. 156.315 PEA in new section at Birkbeck. 1 normal and 1 Short Loan copy (pages 1-14, 237- 251, 253-287)

Tomasello, M. (2000). Primate cognition: Introduction to the issue. Cognitive Science, 24(3), 351-361.

Walker, S.F. (1987a). The evolution and dissolution of language. In Ellis, A. (ed.), Progress in the Psychology of Language. Volume 3. Lawrence Erlbaum: London. pp 28-41 only (Short Loan).  

 

More Additional References (Not normally for further reading)

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