Animals' psychotic acts called uncertain guide

Press, Volume CXV, Issue 33739, 11 January 1975, Page 10

Animals' psychotic acts called uncertain guide

NEW YORK

To what extent can psychotic behaviour induced or occurring naturally in animals be used to understand better such behaviour in human beings? writes Walter Sullivan in the “New York Times.”

This question, applicable to much current research in psychology, was the theme of a conference that exposed a wide range of recent findings in the field. It was argued that, had it not been for animal studies, notably those with monkeys, the full, lifelong importance of the motherinfant bond would never have been appreciated. It was reported by Dr Robert A. Hinde, of Cambridge University, that in rhesus monkeys the effects of a six-day mother-infant separation were still evident in the infant’s adult behavior two years later.

Yet warnings resounded regarding too literal application of animal findings tg human beings. Dr Stephen Suomi, of the group at the University of Wisconsin that began studying the maternal bond in monkeys some 15 years ago, cautioned that “monkeys are not furry little men with tails.” Variations

Furthermore, a number of participants, including Dr Pierre Pichot, of the University of Paris, noted that behavioural responses to various forms of stress, as well as to drugs, vary markedly from species to species.

For tfcis reason, Dr Pichot said, ’‘we are very far from having animal

models of psychotic behaviour in man.” In an interview Dr Pichot pointed out that the chemistry of the central nervous system varied even between ethnic groups of man. Orientals, for example, respond quite differently from Occidentals to drugs used in psychotherapy, he said, and even in so homogeneous a population as the Swedes there are marked differences. If there are such variations within the human species, he said, it is even more challenging to apply animal findings to human beings. But despite these limits he termed animal experiments potentially extremely rewarding. Motivation Dr Jay Weiss, of Rockefeller University, told of experiments with rats and dogs on the behaviour pattern sometimes referred to as “learned helplessness” following prolonged exposure to some form of inescapable stress. Some researchers believe this lies at the basis of some human disorders. Dr Weiss, however, challenged the idea that this is a long-term “learned” effect. Instead, he described evidence that it arises from a chemical change in which the brain is depleted in catecholamine, notably norepinephrine. This apparently turns off the animal’s motivation for avoidance, causing it to face the stress in a helpless manner.

However, once the stress — in the form of electric shocks, for example — ends, the norepinephrine level of the brain returns

to normal and avoidance behaviour is restored. The work in Wisconsin described by Dr Suomi was initiated some 15 yeans ag by Dr Harry F. Harlow. who moderated one of the sessions. Separation A major area of study has been “anaclytic depre' sion,” a condition arising in the infant following earlv separation from its mother. In rhesus monkeys this leads, at first to a protest stage of crying and agitation, followed by a strge of “depression" or "despair” marked by selfclasping and huddling. The effect. Dr Suomi said, us strikingly like the depression that occurs in human children under similar circumstances. When rhesus infants are raised with other infant monkeys, he reported, they develop attachment.s to one another that to some extent mimic the mother-child bond. During the first day of a four-day separation such monkey babies cry in vociferous protest. For the last two days they roll into a ball typical of the depressed state. When reunited with their peers, they have an "enormous tendency” to cling to one another, Dr Suomi asserted. Depression The monkey experiments may aiso cast light on adult forms of depression, Dr Suomi said, but the link is less clear. Dr Mary Salter Ainsworth of Johns Hopkins University, a specialist in mother-child relations, questioned the validity of conclusions on depression derived from laboratory experiments with monkeys. The baby monkeys, she said, when taken from their mothers, are placed in an environment comparable to “solitary prison confinement,” which, she suggested, cannot be equated with conditions typical of those that lead to human depression.