An Open-Source Wireless Electrophysiological Complex for In Vivo Recording Neuronal Activity in the Rodent's Brain.

Multi-electrode arrays (MEAs) are a widely used tool for recording neuronal activity both in vitro/ex vivo and in vivo experiments. In the last decade, researchers have increasingly used MEAs on rodents in vivo. To increase the availability and usability of MEAs, we have created an open-source wireless electrophysiological complex. The complex is scalable, recording the activity of neurons in the brain of rodents during their behavior. Schematic diagrams and a list of necessary components for the fabrication of a wireless electrophysiological complex, consisting of a base charging station and wireless wearable modules, are presented.

Non-Gaussian Distributional Analyses of Reaction Times (RT): Improvements that Increase Efficacy of RT Tasks for Describing Cognitive Processes.

This didactic aims of this review are to demonstrate the advantages of examining the entire reaction time (RT) distribution to better realize the efficacy of mental speed assessment in clinical neuropsychology. RT distributions are typically non-normal, requiring consideration of a host of statistical issues. Specifically, the appropriate model of the mental speed task's distribution (e.g., ex-Gaussian, Weibull, Normal-Gaussian, etc.) must be determined to know what parameters can be used to characterize test performance. While RT mean and standard deviation are typically used to characterize clinical performance, these parameters are usually inappropriate because RT performance rarely conforms to a normal-Gaussian distribution. For illustrative purposes, a tutorial for examining the entire RT distribution is provided that demonstrates differences between an Attention Deficit/Hyperactivity and a neurotypical group of college students. While such analyses are descriptive, it is important to characterize test performance in the context of a theoretical model of RT performance. Therefore, the tutorial includes interpretation that uses the Diffusion model (Ratcliff Psychological Review, 85, 59-108, 1978), which assumes an ex-Gaussian distribution. It is concluded that current results conform to a large literature demonstrating a more nuanced understanding of cognition afforded by non-Gaussian analysis of RT. This literature is compelling neuropsychology to enlarge assessment technology beyond the limitations of paper-and-pencil instruments.

Effort in college undergraduates is sufficient on the word memory test.

A prior report found unusually high rates of performance validity test (PVT) failure in undergraduate research participants (31%-56%). The present study examined 110 undergraduate volunteers in three conditions (positive, neutral, or negative demand characteristics) in either an easy to hard or a hard to easy progression of neuropsychological tests using the Word Memory Test PVT. Neither demand characteristics nor test order had a substantial effect on test performance, and only a 6.4% failure rate was found on the PVT. These results suggest that neuropsychological testing experiments are completed faithfully by the vast majority of college undergraduates, although excluding the small number of participants failing PVTs would strengthen the internal validity of most studies.

Construct and criterion validity of the comprehensive trail making test in children and adolescents with traumatic brain injury.

The current study examined the construct and criterion validity of the Comprehensive Trail Making Test (CTMT) when used to evaluate children and adolescents with traumatic brain injury (TBI). Participants included 100 children and adolescents, 50 who had sustained TBI and 50 normal comparisons (NC). Analyses indicated that the CTMT factor scores were significantly correlated with tests of perceptual organizational ability, processing speed, and motor function and provided support for its construct validity. Additionally, correlations between the various CTMT scores suggested that a different pattern of associations was present in the TBI group compared to the NC group. Finally, the TBI group performed significantly worse (p < .001) on all of the CTMT scores, including each of the five CTMT trails as well as the factor and composite index scores. Results support the construct and criterion validity of the CTMT when used to assess children and adolescents with TBI.