Retraction of Ross and LoLordo findings concerning blocking in serial feature-positive discriminations.

Findings concerning the effectiveness of stimuli from various conditioning procedures in blocking conditioned excitation and occasion-setting functions of an added stimulus in a serial feature-postive discrimination training procedure (LoLordo & Ross, 1987; Ross & LoLordo, 1986, 1987) are retracted. Videotapes on which the published data were based were rescored by 2-5 people, most of whom were uninformed about group memberships of the subjects. In no case did the rescoring confirm any of the orginal findings of blocking. Possible factors contributing to the discrepancies are discussed. The experiments should be repeated with feature stimuli that are less similar to each other and with several scorers, at least one of whom is unaware of the group assignment of the subjects.     

Role of fear in mediating shuttle escape learning deficit produced by inescapable shock

The relation between the shuttlebox escape deficit produced by prior inescapable shock (IS) and fear during shuttlebox testing as assessed by freezing was investigated in rats. IS rats learned to escape poorly and were more fearful than either escapably shocked subjects or controls, both before and after receiving shock in the shuttlebox. However, fear and poor escape performance did not covary with the manipulation of variables designed to modulate the amount of fear and the occurrence of the escape deficit. A 72-hr interval between IS and testing eliminated the escape deficit but did not reduce preshock freezing. Diazepam before testing reduced both preshock and postshock fear in the shuttlebox but had no effect on the escape deficit. Naltrexone had no effect on fear but eliminated the escape deficit. This independence of outcomes suggests that the shuttlebox escape deficit is not caused by high levels of fear in IS subjects.     

The lateralization of language comprehension using event-related potentials

Event-Related Potentials were recorded over occipital and parietal scalp from left- and right-handed adults presented with a language and a non-language visual stimulus using a divided field, "oddball" paradigm. The major finding of interest was that the P300 component was larger over the left than the right hemisphere of the right-handers when the language stimulus was presented to the left hemisphere; there were no hemispheric differences for the left-handers, regardless of field of presentation. These results are discussed in the context of developing noninvasive measures to lateralize language function.     

Locus of information in words and the right visual field effect

The right visual field (RVF) advantage found for the identification or classification of words has usually been interpreted as evidence for left hemisphere language functions. It has more recently been explained as the result of the fact that the most informative part of the word, presumably the beginning, is in a region of better visual acuity. It is not clear from existing evidence that the beginnings of words are in fact more informative. The present study assessed the locus of information in words by deleting either the initial or terminal one or two letters. Subjects were required to generate a completion. Regardless of whether subjects were scored as correct for generating the original target word (as would be appropriate in a naming study) or for producing any legitimate word (as would be appropriate for a lexical decision study), the results indicated that most words have more information in the initial letters. Nevertheless, there are exceptions to this rule, and some words have more terminal information. Equal numbers of words with more initial information and with more terminal information were selected for two visual field studies in order to assess the effect of the locus of information on visual laterality. In neither a lexical decision study nor a naming study did locus of information affect the commonly observed right visual field superiority. Thus the distribution of information is not likely to be a major confounding variable in laterality studies employing horizontally presented words.     

Efficacy of behavioral management and patient education on vascular access cleansing compliance in hemodialysis patients

Compared four treatment conditions to test their ability to enhance compliance with vascular access cleansing (VAC) procedures in a group of 56 hemodialysis patients. The conditions were patient education, behavioral management with monetary incentive, patient education/behavioral management, and attention control. Behavioral observers rated VAC behavior at pretreatment, posttreatment 1-month follow-up, and 1-year follow-up. Knowledge of VAC procedures was also assessed via a questionnaire at pretreatment and posttreatment. Data were analyzed using repeated-measures multivariate analyses of variance. Results indicated that the patients in the education/behavioral, behavioral, and education groups gave significantly more correct answers on our VAC knowledge questionnaires at posttreatment than did patients in the attention control group. Further, patients in the education/behavioral and behavioral groups completed significantly more VAC steps at posttreatment and 1-month follow-up than did patients in the education group and in the attention control group. Differences were not maintained at 1-year follow-up, although more than 50% of the patients were lost to follow-up. Implications of the present findings for behavioral and educational interventions are discussed.     

Adding new information to semantic memory: how much learning is enough to produce automatic priming?

A series of experiments investigated the integration of new vocabulary words into semantic memory and the creation of new associations between preexisting, but previously unrelated, words. The ability of the newly learned vocabulary words and associations to facilitate lexical decisions when serving as primes under conditions associated with automatic processing was used to index integration. The results indicate that very extensive study is necessary for such integration to occur and that it is easier to add a new word to semantic memory than to establish a link between two formerly unconnected words already in semantic memory. The implications of these results for models of semantic memory and the episodic/semantic distinction are considered.     

Do different metamemory judgments tap the same underlying aspects of memory?

We compared the predictions from several kinds of metamemory judgments (on the same set of items), both in terms of their predictive accuracy and in terms of the commonality of predictions. Undergraduates made judgments about the ease with which they could learn each item in a list (ease-of-learning judgments); then they learned every item, either to a minimal criterion of learning or with overlearning, and made judgments about how well they knew each item (judgments of knowing); finally, they returned 4 weeks later for a retention session and made feeling-of-knowing judgments on every time they could not recall, after which a recognition test assessed predictive accuracy. Ease-of-learning judgments had the least predictive accuracy. Surprisingly, however, the recognition of nonrecalled items was predicted equally well by judgments of knowing (made 4 weeks earlier) as by feeling-of-knowing judgments (made immediately prior to recognition). Moreover, those two kinds of judgments were only weakly correlated with each other, which implies that they do not tap memory in the same way.     

Effects of foveal processing difficulty on the perceptual span in reading: implications for attention and eye movement control

Two experiments were conducted to examine the effects of foveal processing difficulty on the perceptual span in reading. Subjects read sentences while their eye movements were recorded. By changing the text contingent on the reader's current point of fixation, foveal processing difficulty and the availability of parafoveal word information were independently manipulated. In Experiment 1, foveal processing difficulty was manipulated by lexical frequency, and in Experiment 2 foveal difficulty was manipulated by syntactic complexity. In both experiments, less parafoveal information was acquired when processing in the fovea was difficult. We conclude that the perceptual span is variable and attentionally constrained. We also discuss the implications of the results for current models of the relation between covert visual-spatial attention and eye movement control in reading.     

Regression analyses of repeated measures data in cognitive research

Repeated measures designs involving nonorthogonal variables are being used with increasing frequency in cognitive psychology. Researchers usually analyze the data from such designs inappropriately, probably because the designs are not discussed in standard textbooks on regression. Two commonly used approaches to analyzing repeated measures designs are considered in this article. It is argued that both approaches use inappropriate error terms for testing the effects of independent variables. A more appropriate analysis is presented, and two alternative computational procedures for the analysis are illustrated.     

Properties of memory for unattended spoken syllables

Whereas previous studies on memory for unattended speech have inadvertently included acoustic interference, the present study examines memory for unattended syllables during a silent period of 1, 5, or 10 s. The primary task was to read silently (Experiments 1-3) or whisper the reading (Experiment 4). Occasionally, when a light cue occurred, the subject was to recall the most recent spoken syllable, as well as the recent reading material. Memory for both the vowels and consonants of the syllables decreased across 10 s, confirming that auditory memory does decay in the absence of acoustic interference. However, the specific patterns of memory decay for vowels versus consonants depended on task demands, including the allocation of attention and the opportunity for subvocal coding. We suggest an account of performance that includes auditory sensory and phonetic memory codes with different properties, used in combination.