Induced subject-relative movement: Persistence of apparent movement of a stationary point after removal of inducing stimulus

It was observed by chance that perceived movement of a stationary spot of light in a dark featureless field persists after its induced movement by a moving frame. When the frame was suddenly occluded, apparent movement of the spot persisted in the same direction as prior induced movement. The effect which is compelling and readily reported and referred to as induced subject-relative movement (ISRM) was confirmed and further investigated in four experiments. In the first, the informal observations of ISRM were confirmed using manual tracking to index perceived movement, and in the second, it was shown to occur only very slightly and briefly when the frame merely stopped. In the third experiment, ISRM was shown to occur following two different paths of induced movement, and in the fourth, not to occur following real movement of the spot, which was almost indistinguishable from its induced movement. It is suggested that the effect arises from the absence of a signal for cessation of perceived movement when the frame disappears.     

Click location and syntactic structure

Four experiments are reported in which Ss had to judge the location of clicks superimposed on recorded sentences. The first experiment showed that the accuracy of locating the clicks was a function of the position of the click in the constituent structure, the greatest accuracy being for clicks at major clause boundaries. The second experiment showed that this effect was independent of migration, i.e., the tendency for judgments to be displaced towards the major clause break. In the third experiment, it was shown that the requirement that S reproduce the sentence did not influence the response distribution. Finally, in the fourth experiment, a small but significant trend for location accuracy to decrease with decreasing separation of the click from the major break was found. However, this trend was much smaller than the differences in accuracy for various positions in the constituent structure. It was concluded that click location accuracy can be used as an index of perceptual processing load during recognition of individual sentences.     

Preventing weight gain in adults: a pound of prevention

This study evaluated the feasibility and effectiveness of a program for weight gain prevention in normal-weight adults. Two hundred nineteen participants were randomized to either weight gain prevention treatment or no treatment for a period of 12 months. Those in the treatment group received monthly newsletters relating to weight management, participated in a financial incentive system, and were offered an optional four-session education course in the sixth month of the program. Results demonstrated high interest in weight gain prevention among individuals who were not objectively overweight. Participation, as measured by return of postcards sent with each newsletter, was approximately 75%. Results after 1 year showed a net weight loss in the group receiving the program of 1.8 lb compared to those in the control group. Eighty-two percent of program participants maintained or lost weight, compared to 56% of the control group. It is concluded that programs for weight gain prevention are feasible in adults and may be more effective than weight loss treatment programs in addressing the problem of community-wide obesity.     

Age differences in acquisition and retention of one-way avoidance learning in C57BL/6NNia and autoimmune mice

Acquisition and 48-h retention of a step-up active avoidance response were studied in separate age groups of C57BL/6NNia mice (aged 1.5, 3.5, 6, 12, or 26 months) and five strains of genetically autoimmune mice differing in life span. The C57BL/6NNia mice showed no change in ability to acquire the avoidance response between 1.5 and 3.5 months, but showed a steady decline in that ability thereafter. Mouse strains with early-onset autoimmune disorder (NZB/B1NJ, MRL/MpJ-lpr, and BXSB/MpJ) showed declines in acquisition capability between 1.5 and 3.5 months of age, whereas mouse strains with mild, late-onset autoimmune disorder (MRL/MpJ- + and NZBWF1/J) showed stable or improved acquisition during that period. Both the C57BL/6NNia and NZB/B1NJ mice showed age-dependent declines in 48-h retention performance by 12 months of age. These findings suggested that while 48-h retention performance deficits were most related to chronological age, avoidance acquisition deficits were related to development of autoimmunity.     

Conditional reflexes and sensory-evoked epilepsy: The nature of the therapeutic process

Studies of conditional reflex therapy for patients with sensory-evoked epilepsy are reviewed and experimental studies in animals reported. The behavioral methods employed in the therapy are reviewed. They are of a conditioning nature and are defined as clinical therapeutic conditioning. Sensory-evoked epilepsy can be induced in animals by conditioning techniques, provided the animal brain has been rendered epileptogenic. Sensory-evoked epilepsy in patients can be made worse by conditioning, and can be changed from one type to another. However, sensory-evoked seizures in humans are not the result of conditional reflexes.     

Orthographic structure versus morphological structure: principles of lexical organization in a given language

Most models of visual word recognition in alphabetic orthographies assume that words are lexically organized according to orthographic similarity. Support for this is provided by form-priming experiments that demonstrate robust facilitation when primes and targets share similar sequences of letters. The authors examined form-orthographic priming effects in Hebrew, Arabic, and English. Hebrew and Arabic have an alphabetic writing system but a Semitic morphological structure. Hebrew morphemic units are composed of noncontiguous phonemic (and letter) sequences in a given word. Results demonstrate that form-priming effects in Hebrew or Arabic are unreliable, whereas morphological priming effects with minimal letter overlap are robust. Hebrew bilingual subjects, by contrast, showed robust form-priming effects with English material, suggesting that Semitic words are lexically organized by morphological rather than orthographic principles. The authors conclude that morphology can constrain lexical organization even in alphabetic orthographies and that visual processing of words is first determined by morphological characteristics.     

Category size effects revisited: frequency and masked priming effects in semantic categorization

Previous work indicates that semantic categorization decisions for nonexemplars (e.g., deciding that TURBAN is not an animal name) are faster for high-frequency words than low-frequency words. However, there is evidence that this result might depend on category size. When narrow categories are used (e.g., Months, Numbers), there is no frequency effect for nonexemplars. This result is confirmed, and is explained in terms of a category search model, which allows a "No" decision to be generated without access to the lexical entry for the target word. This explains the absence of a frequency effect, but not the presence of a strong masked repetition priming effect, which is assumed to have a lexical source. It is shown that this effect may not be lexical, since nonwords also show similar priming. Both of these priming effects disappear when a larger category is used. This pattern of results is explained on the assumption that category search is only possible with small categories, and that tentative category decisions are generated for the unconsciously perceived prime, which leads to a marked response congruence effect.