Do infants reach for perceived objects? A reply to Stiles-Davis

Stiles-Davis proposes that the infants in our experiments (Hofsten & Spelke, 1985) did not reach for perceived objects in order to manipulate them, but rather touched perceived surfaces in order to explore their boundaries. Her commentary raises questions about infants' perception of the boundaries, the unity, and the manipulability of objects. More deeply, it raises the question of what an object is for an infant. We consider each of these questions in turn, in light of our own findings and those of other studies of object-directed reaching, object perception, and the object concept. We suggest that young infants organize the visual world into entities that are bounded, unitary, and manipulable and that infants endow those entities with the core properties of physical objects.     

Text recall in adulthood: The roles of text imagery and orienting tasks

Summary Three experiments were conducted to investigate dual-code theory and the levels-of-processing approach in discourse processing. Three concrete and three abstract tests were constructed to be equivalent in the degree to which they were perceived as concrete vs. abstract. All experiments presented concrete and abstract texts under three orienting tasks. Results of the first experiment showed main effects for both text concreteness and orienting tasks and an interaction that can be described by the lack of a difference between the recall rates for the concrete and the abstract texts under the intentional-learning condition. In the second experiment, longer texts were used and a second trial was introduced. The interaction was not replicated. There were main effects for concreteness, orienting tasks, and trials. The third experiment replicated Experiment 2 with subjects in their late 40s and over 70. Main effects were obtained as before. Age interacted with both orienting task and concreteness, indicating that older adults gain less than middle-aged adults from intentional-learning instructions and benefit less from highly concrete texts. The discussion focuses on the relation of Materials and Subjects as factors to dual-code theory and levels of processing approach.     

The role of binocular information in ball catching

The role of binocular vision in a ball-catching task involving spatial uncertainty was examined in three experiments. In all three experiments, subjects' catching performance was evaluated during monocular and binocular viewing, in normal room lighting and in complete darkness with a luminescent ball. Subjects' performance was found to be significantly better with binocular than with monocular vision, especially under normal lighting conditions. In the second and third experiments, catching performance was evaluated in the presence of minimal visual frames, consisting of a series of light-emitting diodes (LEDs). In Experiment 2, the visual frame consisted of a single plane of LEDs, whereas in Experiment 3, the visual frame consisted of two planes of LEDs. Catching performance was found to be significantly better with the visual frame than in complete darkness, but this was true only for binocular viewing. This result supports the hypothesis that binocular convergence is used to scale perceived space and that this information enables subjects to contact the ball successfully. It was further found that postural sway varied between lighting conditions and that less sway was accompanied by higher performance. There was no effect of binocular viewing in this respect. In general, the results suggest two additive effects of viewing conditions: a direct effect of binocular vision on ball catching and an indirect effect of lighting on postural stability, which, in turn, affects catching performance.     

Conditioned taste and taste-potentiated odor aversions in the Syracuse high- and low-avoidance (SHA/Bru and SLA/Bru) strains of rats (Rattus norvegicus).

Syracuse high- and low-avoidance Long-Evans rats (Rattus norvegicus; SHA/Bru and SLA/Bru) were selectively bred for good and poor active-avoidance learning. However, SLA/Bru animals are superior to SHA/Bru rats in conditioned suppression and passive avoidance learning. In this experiment, saccharin taste and almond odor were the components of a compound conditioned stimulus (flavor) in an illness-induced aversive conditioning paradigm. SLA/Bru rats (n = 17) showed stronger conditioned flavor, taste, and odor aversion than did SHA/Bru animals (n = 18). Unselected Long-Evans rats (n = 18) were intermediate between the selected strains. SLA/Bru and Long-Evans rats showed taste-potentiated odor aversions in this experiment, whereas SHA/Bru animals did not. The results provide evidence that genetic factors, as exemplified by the different strains, are importantly involved in the mechanisms underlying interoceptive and exteroceptive aversive conditioning.     

Interpersonal determinants of attitude change following counterattitudinal behavior

In a test of predictions derived from an identity-analytic model of self-presentational behavior, individuals who privately endorsed positive or negative attitudes about sexual behavior were asked to deliver a prosexuality speech while alone, while watched by observers, or while being watched by observers who questioned the morality of the subject’s actions. Subsequent attitude measures indicated that the subjects who initially adopted negative attitudes justified their behavior by expressing more favorable attitudes about sexuality, but only when no audience witnessed their speech. When an audience was present, these individuals emphasized their lack of choice. In contrast, subjects who privately endorsed positive attitudes publicly expressed less favorable attitudes when their morality was challenged by the observers. These findings suggest that attitude change following counterattitudinal behavior (a) stems from private image-maintenance needs as well as public self-presentational concerns, and (b) is sometimes designed to secure an image of morality as well as an image of consistency.     

Behaviorally treated irritable bowel syndrome patients: a four-year follow-up

Nineteen of 27 patients suffering from Irritable Bowel Syndrome (IBS) who had completed a multicomponent treatment involving progressive muscle relaxation, thermal biofeedback, cognitive therapy and IBS education were located and evaluated 4 yr posttreatment. Seventeen of 19 (89.5, or 63% of the total original sample) rated themselves as more than 50% improved. Six of the 12 patients (50%) who submitted symptom monitoring diaries met our criteria for clinical improvement, i.e. achieving at least a 50% reduction in primary IBS symptom scores. The means on all measures at long-term follow-up were lower than those obtained prior to treatment. When follow-up symptom means were compared with pretreatment means, significant (P less than 0.05) reductions were obtained on abdominal pain/tenderness, diarrhea, nausea, and flatulence.     

Freud, psychoanalysis and the psychosomatic problem

According to the author an unbroken hallucination of the pleasure principle is underlying the vision of mankind as in biotechnical medicine as well as in a concept of science that is reduced to technical progress. Psychosomatics is to overcome the false rationality of such thought.     

A learned change of response to inedible food in Aplysia

Aplysia fasciata attempt to bite and swallow food wrapped in a plastic net, tasting food through holes in the net. Net-enclosed food cannot be swallowed, and becomes cyclically lodged and pushed out of the buccal cavity. Aplysia gradually modify their response to this food, and eventually cease to respond. Twenty-four hours following training, memory is maintained, as shown by savings upon retraining. An essential component of the behavioral plasticity is food becoming stuck within the buccal cavity: when the lips are stimulated without allowing food to enter the buccal cavity, animals stop responding, but training takes longer, and memory is not retained. Savings upon retraining are contingent upon temporal pairing of food upon the lips and stimuli from within the buccal cavity: when lip stimuli and the experience of food stuck within the buccal cavity occur sequentially (rather than simultaneously), 24 hr later, animals are not significantly different from naive subjects.