Observer Effects without Demand Characteristics: An Inductive Investigation of Video Monitoring and Performance

Purpose

The purpose of these two studies was to explore the relationship between video monitoring and quantity of performance in the absence of demand characteristics.

Design/methodology/approach

Data were gathered via two experiments involving business students working on a motor task. Participants were randomly assigned to the monitored and unmonitored conditions. Experiment 1 (n = 75) was inductive while Experiment 2 (n = 139) was partially inductive.

Findings

Experiment 1 showed that monitored participants’ performance was lower than that of unmonitored participants. Further, monitoring reduced outliers, increased interquartile variance, and normalized the distribution. Experiment 2 replicated the effect of monitoring on performance controlling for cognitive ability and emotions, demonstrated that negative emotions interacted with monitoring condition, and suggested that differences in performance were not due to cheating or variation in task-related strategies. We offer a grounded theory of video monitoring proposing that different implicit decision rules are activated when people are monitored as compared to when they are not monitored.

Implications

Future research needs to determine the extent to which our results extend to similar settings in the workplace and to other forms of observation. At this time, we believe organizations should carefully consider the consequences of electronic monitoring. Controlling expectations in the lab or workplace does not necessarily eliminate the independent effect of monitoring. Therefore, researchers must beware misinterpretation of effect sizes and overlooking the role of observation in their data.

Originality/value

These studies demonstrate that video monitoring can create observer effects in the absence of demand characteristics. Our inductive approach revealed the nature of the effects beyond mean differences and served as the basis for developing a testable theory of monitoring that goes beyond what was previously known.     

Walking dreams in congenital and acquired paraplegia

To test if dreams contain remote or never-experienced motor skills, we collected during 6 weeks dream reports from 15 paraplegics and 15 healthy subjects. In 9/10 subjects with spinal cord injury and in 5/5 with congenital paraplegia, voluntary leg movements were reported during dream, including feelings of walking (46%), running (8.6%), dancing (8%), standing up (6.3%), bicycling (6.3%), and practicing sports (skiing, playing basketball, swimming). Paraplegia patients experienced walking dreams (38.2%) just as often as controls (28.7%). There was no correlation between the frequency of walking dreams and the duration of paraplegia. In contrast, patients were rarely paraplegic in dreams. Subjects who had never walked or stopped walking 4–64 years prior to this study still experience walking in their dreams, suggesting that a cerebral walking program, either genetic or more probably developed via mirror neurons (activated when observing others performing an action) is reactivated during sleep.     

Cross-structural priming: prepositional phrase attachment primes relative clause attachment

In this paper we show that attachment height (high vs. low attachment) of a modifier to a complex noun phrase (CNP; e.g., "the servant of the actress"), can be primed between dissimilar syntactic structures. In a sentence completion experiment, we found that the attachment height of a prepositional phrase (PP) in the prime sentence primed the attachment height of a relative clause (RC) in the target sentence. This cross-structural priming effect cannot be explained in terms of the priming of specific phrase-structure rules or even sequences of specific phrase-structure rules (Scheepers, 2003), because the attachment of a PP to a CNP is generated by a different phrase-structure rule than the attachment of an RC. However, the present data suggest that the location at which the RC is attached to the CNP is mentally represented, independent of the specific phrase-structure rule that is attached, or by extension, that the abstract hierarchical configuration of the full CNP and the attached RC is represented (Desmet & Declercq, 2006). This is the first demonstration of a cross-structural priming effect that cannot be captured by phrase-structure rules.     

Integration of visual information for saccade production

To foveate a visual target, subjects usually execute a primary hypometric saccade (S1) bringing the target in perifoveal vision, followed by a corrective saccade (S2) or by more than one S2. It is still debated to what extent these S2 are pre-programmed or dependent only on post-saccadic retinal error. To answer this question, we used a visually-triggered saccade task in which target position and target visibility were manipulated. In one-third of the trials, the target was slightly displaced at S1 onset (so-called double step paradigm) and was maintained until the end of S1, until the start of the first S2 or until the end of the trial. Experiments took place in two visual environments: in the dark and in a dimly lit room with a visible random square background. The results showed that S2 were less accurate for shortest target durations. The duration of post-saccadic visual integration thus appears as the main factor responsible for corrective saccade accuracy. We also found that the visual context modulates primary saccade accuracy, especially for the most hypometric subjects. These findings suggest that the saccadic system is sensitive to the visual properties of the environment and uses different strategies to maintain final gaze accuracy.     

Hippocampal tauopathy in tau transgenic mice coincides with impaired hippocampus-dependent learning and memory, and attenuated late-phase long-term depression of synaptic transmission

We evaluated various forms of hippocampus-dependent learning and memory, and hippocampal synaptic plasticity in THY-Tau22 transgenic mice, a murine tauopathy model that expresses double-mutated 4-repeat human tau, and shows neuropathological tau hyperphosphorylation and aggregation throughout the brain. Focussing on hippocampus, immunohistochemical studies in aged THY-Tau22 mice revealed prominent hyper- and abnormal phosphorylation of tau in CA1 region, and an increase in glial fibrillary acidic protein (GFAP) in hippocampus, but without signs of neuronal loss. These mice displayed spatial, social, and contextual learning and memory defects that could not be reduced to subtle neuromotor disability. The behavioral defects coincided with changes in hippocampal synaptic functioning and plasticity as measured in paired-pulse and novel long-term depression protocols. These results indicate that hippocampal tauopathy without neuronal cell loss can impair neural and behavioral plasticity, and further show that transgenic mice, such as the THY-Tau22 strain, might be useful for preclinical research on tauopathy pathogenesis and possible treatment.     

Morphological awareness: development trends and patterns of evolution in kindergarten and primary education

We present a study that investigates changes in the acquisition and development of morphological awareness in children from 5 to 7 years old. This investigation was carried out on three separate occasions over two academic years, in which morphological awareness was assessed according to two levels. The data indicate an increase in the morphological awareness development from the kindergarten to primary education, verifying the acquisition in the first instance of the morphological judgment level and secondly, of morphological production level. It also generates a pattern of acquisition of the various parameters that make up morphology.     

Amodal completion, depth stratification, and illusory figures: a test of Kanizsa's explanation.

Subjective contours have been explained by Kanizsa as being a consequence of amodal completion of incomplete figures. According to the theory of amodal completion, figural incompleteness triggers the emergence of an illusory object superimposed on the gaps in the inducers, which in turn hide parts of the pattern, thus suggesting that the plane of the illusory object must always be seen to be above the plane of the inducers. A figure was created in which subjective contours are seen despite the fact that the perceived depth relationships run counter to that required by the theory of amodal completion. In four experiments, this depth relationship is confirmed by using direct and indirect measures which assess both registered and apprehended depth. By emphasizing a logical inconsistency in the explanation based on amodal completion, the results show that amodal completion, at least in Kanizsa-like patterns, cannot be considered as a causal factor for subjective contour figures.     

Modal Logics of Reactive Frames

A reactive graph generalizes the concept of a graph by making it dynamic, in the sense that the arrows coming out from a point depend on how we got there. This idea was first applied to Kripke semantics of modal logic in [2]. In this paper we strengthen that unimodal language by adding a second operator. One operator corresponds to the dynamics relation and the other one relates paths with the same endpoint. We explore the expressivity of this interpretation by axiomatizing some natural subclasses of reactive frames. The main objective of this paper is to present a methodology to study reactive logics using the existent classic techniques.