The present study was designed to assess the physiological correlates of learned helplessness in human subjects. One group of subjects was pretreated with a series of inescapable aversive tones, and the degree of impairment was measured on a subsequent solvable anagram solution task. These subjects were compared with a group pretreated with escapable aversive tones and a control group which passively listened to the tones without attempting to escape them. The results replicated the learned helplessness effect: The group pretreated with inescapable tones demonstrated greatly impaired performance at solving anagrams relative to the other groups. Moreover, the learned-helplessness group demonstrated lower tonic skin conductance levels, smaller phasic skin conductance responses, and more spontaneous electrodermal activity relative to the group pretreated with escapable tones. These are symptoms which some researchers have claimed to be associated with clinical depression.

In three experiments we examined aspects of the word inferiority effect and word frequency disadvantage for letter detection. In Experiment 1 we tested a prediction derived from a hypothesis based solely on attentional factors. Adult subjects performed one of two secondary detection tasks while reading for comprehension. The inferiority effects were obtained only when the secondary task was letter detection, not when nonletter targets were used in the secondary task. This finding is inconsistent with the attentional hypothesis, but is consistent with the unitization hypothesis of Healy and Drewnowski (1983). In Experiments 2 and 3 we found that manipulation of the need to read for comprehension had little influence on the letter-detection inferiority effects, but a strong influence on the effects involving the detection of nonletter targets. These results are discussed in terms of their implications concerning processing system flexibility.

A familiarity effect in these experiments is defined as a subject's ability to respond more rapidly to a familiar stimulus than to an unfamiliar stimulus. In the first experiment, responding faster to familiar letters (upright) than to unfamiliar letters (inverted) occurred only when the two stimulus types were presented in a random order. These results were interpreted in terms of the effects of processing strategy changes. The second experiment compared the responding of Japanese and American subjects to Japanese and English letters. American subjects responded faster to English letters and Japanese subjects responded faster to Japanese letters. This familiarity effect was obtained even when stimulus presentation was organized by letter type and subjects knew which letter type to expect. The final experiment compared English and Japanese letters in a memory search task. The rate of search for Japanese letters was slower than for English letters. However, no zero-intercept difference was obtained. The evidence indicates that familiarity does not affect an initial encoding process, but it can affect a comparison process.

The effects of learned control of heart rate deceleration and therapeutic expectancy set in reducing speech anxiety were investigated in a factorial design employing 36 speech-anxious subjects. Heart rate control training and no heart rate control training were each paired with high-therapeutic-expectancy and neutral-expectancy instructions, in order to assess the individual and combined effects of the two factors. Results demonstrated that learning to control heart rate deceleration led to a significant reduction in self-report, physiological (heart rate and skin conductance level), and overt signs of anxiety, relative to the no-heart-rate control condition. High-therapeutic-expectancy instructions also contributed to a reduction in self-reported anxiety. These results demonstrate that learned heart rale control is an effective therapeutic technique for reducing anxiety.

An attempt was made to obtain Ll-shaped masking functions in two metacontrast experiments. Trained Ss judged whether a square test stimulus (TS) was bright or dim. The TS was presented alone or in conjunction with an adjacent pair of square masking stimuli (MS) whose energy equaled the bright TS. The stimulus onset asynchronies (SOA) ranged from 0 to 125 msec. The task minimized the role of apparent movement cues as a reliable basis for judgment. Similar studies have employed TS plus MS vs MS alone as the alternatives, allowing apparent movement to be a cue. Brightness accuracy was a If-shaped function of SOA. This finding is consistent with neural-net models (Weisstein, 1968). However, analysis of Ss' response bias suggested an alternative explanation involving the MS as a comparison stimulus at short SOA. It was concluded that U-shaped masking functions are also consistent with theories based upon independent component processes, e.g., Schurman and Eriksen (1970) and Uttal (1970).Metacontrast refers to a performance decrement or a decrease in phenomenonal brightness of a test stimulus (TS) produced by an adjacent but nonoverlapping masking stimulus (MS) presented concurrently or shortly after TS. The term "masking function" describes the relationship between the response measure and the stimulus onset asynchrony (SOA) separating TS onset from MS onset. These masking functions typically are at a minimum at O-msec SOA (concurrent TS-MS onset) and increase monotonically to the control level (TS alone) between 100-and 200-msec SOA. However, U-shaped functions with minima at 25-to 50-msec SOA have also been reported. The conditions giving rise to this phenomenon are quite controversial. Equal TS and MS energies seem a necessary (Weisstein, 1968) but not sufficient condition (Schurman, 1972;Schiller & Smith, 1966) for U-shaped masking.Schurman (1972) has described two groups of investigators who have been in conflict over If-shaped masking. One group is represented by Weisstein (1968) and Haber (1970), among others, They tend to define perception in phenomenological terms and to use brightness matching and magnitude estimation measures in their most recent metacontrast studies. Conceptually, they view metacontrast as a unitary phenomenon. Weisstein's (1968) elegant neural-net model, based upon principles of lateral inhibition, typifies this approach. She attempts to demonstrate how differences between U-shaped and monotonic masking functions are the