Semantic Factors in the Production of Number Agreement

This paper examines the role of semantic factors in the production of subject–verb number agreement. As an ostensibly grammatical process, number agreement provides an interesting case for examining the flow and interaction of semantic and syntactic information through the language-production system. Using a sentence-completion task, agreement errors can be elicited from subjects by presenting them with sentence fragments containing a complex noun-phrase, in which the nonhead noun is plural (e.g., The key to the cabinets...WERE missing.). Previous research has demonstrated that the probability of making an error can be affected by varying the properties of the nouns in the complex noun phrase. By investigating which variables do and do not affect error rates, constraints on the flow of information through the production system can be inferred. In three experiments, we investigated the possible effects of three different semantic manipulations of the nouns in the complex NP: animacy, semantic overlap, and plausibility of modification by the sentence predicate. We found that both animacy and semantic relatedness had reliable effects on error rates, indicating that the mechanism involved in implementing agreement cannot be blind to semantic information. However, the plausibility with which each noun could serve as the subject of the sentence predicate had no effect on error rates. Taken together, these results suggest that while semantic information is visible to the agreement mechanism, there are still constraints on when this information can affect the process. Specifically, it may be the case that only information contained within the complex NP is considered for the purposes of implementing agreement.     

Oblique factors and components with independent clusters

Relationships between the results of factor analysis and component analysis are derived when oblique factors have independent clusters with equal variances of unique factors. The factor loadings are analytically shown to be smaller than the corresponding component loadings while the factor correlations are shown to be greater than the corresponding component correlations. The condition for the inequality of the factor/component contributions is derived in the case with different variances for unique factors. Further, the asymptotic standard errors of parameter estimates are obtained for a simplified model with the assumption of multivariate normality, which shows that the component loading estimate is more stable than the corresponding factor loading estimate.     

Effects of psychological defense on processing of neutral stimuli indicated by event-related potentials (ERPs)

The Defense Mechanism Test (DMT) is claimed to identify personnel with a high risk for accidents. A new explanation for why the DMT seems to predict performance when survival depends on split second decisions is proposed. Sixteen right-handed, adult male students were tested with the DMT and with an ERP paradigm (two sine wave tones, presented binaurally). Each subject was tested with a one-stimulus paradigm, and a passive and an active oddball paradigm. Under the passive oddball condition, High defensive subjects differed from Low, having significantly smaller N2 amplitudes (low immediate perception), and significantly larger P3 amplitudes (rely on later associative mechanisms). High defensive subjects seem to have less ability to perceive the environment correctly immediately. This slowness may be fatal when life depends on split second decisions. The fundamental neurophysiological difference may also be the basis for the very complex cognitive and perceptual mechanisms involved in psychological defense mechanisms.     

Countering conspiracy theory beliefs: Understanding the conjunction fallacy and considering disconfirming evidence

Research suggests that a number of cognitive processes—including pattern perception, intentionality bias, proportionality bias, and confirmation bias—may underlie belief in a conspiracy theory. However, there are reasons to believe that conspiracy theory beliefs also depend in part on a failure to understand the probability of actual events allegedly supporting those conspiracy theories as well as a failure to entertain disconfirming evidence that may contradict those beliefs. Study 1 examines the relationships between general beliefs in conspiracy theories, belief in a novel conspiracy theory, conjunctive error propensity, and the propensity to consider disconfirming evidence. Study 2 investigates the roles of confronting both the propensity to make conjunctive errors and the failure to consider disconfirming evidence in changing conspiracy theory beliefs as well as attitudes associated with those beliefs. The results of both studies suggest that corrections to one's propensity to make conjunctive errors and mindful consideration of disconfirming evidence may serve as viable methods of self-persuasion pertaining to conspiracy theory beliefs.     

Topographical variations in behavior during autoshaping, automaintenance, and omission training

Three pigeons were exposed to an autoshaping and automaintenance procedure while a computer-controlled tracking system continuously recorded the position of the bird's head as it moved freely in the experimental chamber. Although only 2 birds pecked the key during the conditional stimulus (red keylight), all 3 birds exhibited stable patterns of approaching the conditional stimulus and withdrawing from the intertrial stimulus (white keylight). Subsequent exposure to an omission procedure, in which pecks on the red key cancelled the presentation of food upon the termination of the red keylight, greatly reduced key pecking, but approaching and pecking in the vicinity of the conditional stimulus were maintained at high levels. When the omission contingency was removed key pecking increased. During all phases the birds withdrew from the area of the white key and engaged in repetitive back-and-forth or circuiting movements during this intertrial stimulus. The data document (a) the strong control the conditional stimulus in autoshaping and automaintenance exerts over approach to the key and pecking motions whether or not the conditional stimulus elicits key pecking at a high level; and (b) withdrawal from the vicinity of the key and the occurrence of stereotypic behavior during the intertrial interval.     

EXPERIMENTER CALCULATION ERRORS: A POTENTIAL FACTOR AFFECTING INTERPRETATION OF RESULTS1

Following a study of socially withdrawn children, it was noted that checks of experimenter calculations indicated discrepancies. The present study investigated the magnitude and direction of experimenter errors in data computations. Two full-time research assistants, who served as experimenters, processed the behavioral observation data. These experimenters were referred to as the subjects in this study. Standard data values, against which the subjects' computations were compared, were established by two other research assistants and a computer staff. The results indicated that experimenters' original data values disagreed with the standard data values. The daily errors showed considerable variability for both experimenters. The specific factors accounting for this variability could not be identified, although frequency of experimenter responses required to obtain rate and duration data, time spent calculating, and complexity of task were suggested as possible contributing variables. While disagreements occurred across all experimental days, the magnitude of differences was generally small. An examination of direction of differences in both experimenters' data showed no systematic trends in favor of the experimental hypothesis. Rather, there appeared to be a trend in the other direction. This study suggests that the same research decisions would have been made during the original investigation using either set of data.     

Autoshaping in the rat: Effects of omission on the form of the response

Two experiments were conducted to investigate the effect of an omission contingency on behavior related to and characterizing autoshaped lever contacts in the rat. In Experiment I an omission contingency imposed on autoshaped lever contacts forceful enough to produce a press (.078N) resulted in a significant decrease in lever presses, but had no effect on frequency of lever touches (contacts of insufficient force to produce a press) or rate of food tray entry during lever presentation. In contrast, rats which received a similar number of lever-food pairings, but whose behavior had no programmed consequences (yoked control subjects), showed an increase in lever press rate, a significant decrease in rate of food tray entry, and no change in rate of lever-touches. In Experiment II, the effect of a similar omission contingency on the topography of lever contact responses was investigated. Prior to omission training subjects contacted the lever primarily by pawing it. Following omission training this behavior was suppressed, with a subsequent increase in lever contacts characterized as nosing. Yoked control subjects showed no significant changes in lever contact topography. The results indicate that (1) an omission contingency does not simply eliminate wholesale those topographies which incur the contingency but produces subtle adaptive changes in lever contact topography; and (2) the nature of the autoshaped response in the rat does not appear to be rigid enough to depend solely upon the nature of the unconditioned stimulus or the conditioned stimulus, but can also be determined by the relationships existing between the animal's behavior and these stimuli.     

Selective sensitivity of schedule-induced activity to an operant suppression contingency.

The sensitivity of pigeons' schedule-induced activity to operant consequences was studied in two experiments. During a 30-s interval between food presentations, a keylight stimulus brightened incrementally. Stable terminal key pecking and interim locomotor activity developed. An operant "setback" contingency was applied to activity. The contingency arranged for locomotor movements (detected by a nine-panel floorboard) to be followed by a resetting of the keylight brightness to a dimmer value and a 1-s delay of reinforcement (for individual responses). Experiment 1 showed that activity patterns were highly sensitive to their operant consequences. Accompanying key-peck rates were only transiently affected. In Experiment 2, the setback contingency was imposed during restricted portions of the trial, and differential operant control of activity was demonstrated. However, birds in this study produced higher rates of key pecking as activity rates were reduced. These results suggest that although schedule-induced activity arises in response to the temporal arrangement of stimulus events, this behavior may retain considerable sensitivity to response-consequence relations.     

"Turning back the clock" on serial-stimulus sign tracking.

Two experiments examined the effects of a negative (setback) response contingency on key pecking engendered by a changing light-intensity stimulus clock (ramp stimulus) signaling fixed-time 30-s food deliveries. The response contingency specified that responses would immediately decrease the light-intensity value, and, because food was delivered only after the highest intensity value was presented, would delay food delivery by 1 s for each response. The first experiment examined the acquisition and maintenance of responding for a group trained with the contingency in effect and for a group trained on a response-independent schedule with the ramp stimulus prior to introduction of the contingency. The first group acquired low rates of key pecking, and, after considerable exposure to the contingency, those rates were reduced to low levels. The rates of responding for the second group were reduced very rapidly (within four to five trials) after introduction of the setback contingency. For both groups, rates of responding increased for all but 1 bird when the contingency was removed. A second experiment compared the separate effects of each part of the response contingency. One group was exposed only to the stimulus setback (stimulus only), and a second group was exposed only to the delay of the reinforcer (delay only). The stimulus-only group's rates of responding were immediately reduced to moderate levels, but for most of the birds, these rates recovered quickly when the contingency was removed. The delay-only groups's rates decreased after several trials, to very low levels, and recovery of responding took several sessions once the contingency was removed. The results suggest that (a) sign-tracking behavior elicited by an added clock stimulus may be reduced rapidly and persistently when a setback contingency is imposed, and (b) the success of the contingency is due both to response-dependent stimulus change and response-dependent alterations in the frequency of food delivery. The operation of the contingency is compared with the effects of secondary reinforcement and punishment procedures.     

Automaintenance in guinea pigs: effects of feeding regimen and omission training

Behavior maintained by stimulus-reinforcer pairings was examined. Guinea pigs maintained at 85 per cent of free-feeding weights reliably contacted a retractable lever presented before delivery of a single piece of guinea-pig chow or a 45-milligram guinea-pig pellet. When animals were given free access to one food and received the second food preceded by the lever, contact responses persisted. Such responses seldom occurred when a single food was freely available and was also delivered after lever presentation. Introduction of an omission training (negative automaintenance) procedure, in which lever contacts resulted in lever retraction and prevented food delivery, strongly reduced lever contacts. Observation indicated that mouthing the food cup, instead of the lever, became the prominent behavior during the prefood stimulus under the omission training procedure.