Serial learning by rhesus monkeys: II. Learning four-item lists by trial and error.

Abstract

Three rhesus macaque monkeys were trained to produce novel 4-item lists (A -H> B -> C -+*• D) on which all items were displayed from the start of training. Subjects were previously trained to produce 4-item lists by adding one item at a time (A, A -> B, A -» B -> C, and A -» B -> C -> D; lists K. B, Swartz ct al., 1991). Those lists could be mastered by responding to each new item last. To learn lists on which all items were displayed from the start of training, subjects had to recall the consequences of errors and correct responses to each item. Errors ended the trial; correct responses to A. B, or C allowed the trial to continue. A correct response to D produced food reward. Although the probability of executing a 4-item list correctly by chance was .04, each subject mastered 4 novel 4-item lists by trial and error. The ability of monkeys to use a trial-and-enor strategy to learn novel lists provides a basis for studying the development of serial expertise in animals.The experiment described in this article concerns the development of serial expertise in monkeys, specifically, a monkey's ability to memorize arbitrary sequences of arbitrary stimuli. Recent research has shown that cebus apella (D'Amato & Colombo, 1988;

Sequential recall of meaningful and arbitrary sequences by orangutans and human children: Does content matter?

“…Although human and non-human primates are capable of sequencing both arbitrarily or meaningfully related items after a training period (D'Amato and Colombo 1988; Guyla and Colombo 2004;Swartz et al 1991Swartz et al , 2000Terrace 2001), and although monotonic sequences are easier to learn and recall than non-monotonic ones (Brannon and Terrace 2000;Ohshiba 1997;Terrace and McGonigle 1994), young human children and non-human great apes, as represented by orangutans, do not use content cues spontaneously to sequence items without some practice and training. The fact that older children (5-and 7-year-olds) use these cues readily (Terrace and McGonigle 1994), while younger children (3-and 4-year-olds) and orangutans do not, suggests that seriating items this way is a culturally learned behavior.…”

“…This design requires that participants focus on the content of the pictures when responding with the correct sequence; attention to the spatial position of a picture offers no clue as to the ordinal position of that picture in the sequence. The cognitive task has been used in numerous experiments with pigeons, monkeys, apes, and humans (Ohshiba 1997;Subiaul et al 2004Subiaul et al , 2007Swartz et al 1991Swartz et al , 2000Terrace 1991Terrace , 2005Terrace et al 2003). Previous research into serial memory has generally used arbitrarily related items that are not inherently ordered by visual cues like size, for example (Guyla and Colombo 2004;Harris et al 2007;Subiaul et al 2004).…”

“…Research with sequential tasks implemented on touch-sensitive screens has shown that rhesus monkeys can learn a sequence of items (e.g., four distinct pictures) when given incremental training starting with the first item in the list (Swartz et al 1991) or when given progressively complex trial-and-error learning conditions (Swartz et al 2000). Animals can also develop knowledge of the ordinal positions of specific items in a sequence (D'Amato and Colombo 1988;Harris et al 2007;Pfuhl and Biegler 2012;Scarf and Colombo 2011).…”

Memory of Ordinal Number Categories in Macaque Monkeys

“…Monkeys trained on a series of images (e.g., A-B-C-D-E) successfully report the order of a random pair of images, including nonsequential pairs (A-C, B-E, etc. ; Terrace et al, 2003;Swartz et al, 1991Swartz et al, , 2000Colombo, 1988, 1990). Similarly, monkeys trained on a sequence of pairs (A-B, B-C, etc.…”

“…Lists with maintained ordinal position were acquired rapidly and virtually without error, whereas lists with items in changed positions were as difficult to learn as lists with novel items. In another experiment, it was found that after monkeys were trained on lists of up to seven items of photographs, they could immediately report the order of any random pair chosen not only from a given list (Swartz et al, 1991(Swartz et al, , 2000D'Amato and Colombo, 1988), but also from different lists (e.g., 1 Hebrew University, Israel, 2 Università di Roma La Sapienza, Italy the first item from List 6 and the fifth item from List 2; Terrace et al, 2003). This transfer to derived lists or pairs supports the conclusion that the monkeys had acquired knowledge about each item's ordinal position.…”