Cognition

The midline nuclei of the thalamus, previously characterized as “nonspecific” with undifferentiated connections with the cortex, have been shown to distribute in a specific and highly organized manner to subcortical and cortical structures. The midline thalamus consists of the paraventricular (PV) and paratenial (PT) nuclei, dorsally, and the reuniens (RE) and rhomboid (RH) nuclei, ventrally. The PV and RE nuclei have been examined to a far greater extent than either the PT or RH and have been shown to be involved in various affective and cognitive functions. Generally, PV is more associated with emotional and motivated behaviors such as arousal, feeding, drug addiction, fear, and anxiety, whereas RE is more involved in cognitive and mnemonic functions -- as RE represents a critical bridge between the medial prefrontal cortex (mPFC) and the hippocampal formation.
As afferent projections to PT have not been systemically described, we examined the input to PT comparing it with that to PV, using retrograde anatomical tracer, fluorogold (FG). We found PT and PV are almost exclusively targeted by ‘limbic’ structures of the forebrain. Whereas afferents to PT and PV originate from very similar sources, PT receives stronger input from the cortex and PV from subcortical structures. Notably, PT receives prominent input from the mPFC and orbital (ORB) cortices, two regions associated with cognitive flexibility and decision making.

Cognitive flexibility is crucial for efficient goal-directed behavior, especially in rapidly changing environments. While recent studies have consistently shown enhanced theta power and synchronization in the frontoparietal network during flexible task-switching, direct evidence establishing a causal link between theta-rhythm brain oscillation and cognitive flexibility remains limited. In this study, we applied transcranial alternating current stimulation (tACS) to the frontoparietal network at a theta frequency (6 Hz) with a phase difference of either 0° (inphase) or 180° (antiphase) to explore its impact on task-switching performance. The results showed no significant tACS modulation effects on switch costs or neural oscillatory synchronization in the frontoparietal network. However, a consistent negative correlation was observed between frontoparietal theta power in the early time window of cue-target interval and task switching performance, implying the close relationship between proactive control in task switching and frontoparietal theta activities.

Under the expected warmer temperatures due to climate change, sea turtle embryos may be subjected to thermal conditions detrimental to nest success and hatchling quality; one trait which may be negatively affected is cognitive ability. In this study, loggerhead sea turtle eggs were acquired from Boca Raton, FL and lab incubated under two female-producing temperatures: an “optimal” temperature of 31°C and a sublethal temperature of 33°C. Cognitive ability of post-hatchlings, assessed via associative learning and reversal was investigated using a y-maze. The sublethal temperature decreased incubation duration, hatch success, hatchling growth rates and produced smaller hatchlings with significantly more scute anomalies. Hot hatchlings performed worse on the reversal, taking longer to train, and thus hint at an effect of incubation temperature on cognitive flexibility in loggerhead turtles. With temperatures rising on beaches in South Florida, this study provides evidence of further potential threats to hatchling quality and potentially even survival.

Controversy surrounds the idea that bilingualism leads to enhanced executive function (EF) and brain volume changes, potentially leading to delays in cognitive decline and dementia onset. The purpose of this research was to explore these claims in a sample of elderly monolinguals and bilinguals. This study explored gray matter volume (GMV) in 214 monolinguals and bilinguals (Mage = 71.21, SD = 7.53) who were cognitively normal (CN) or diagnosed with Mild Cognitive Impairment (MCI) or dementia. Neuropsychological performance was also examined between CN and MCI monolinguals and bilinguals (N = 153) across two visits. Scores from the Digit Span Backwards, Stroop interference, Trail Making Test A minus Trail Making Test B, and category fluency average scores were used. Magnetic Resonance Imaging (MRI) brain regions associated with memory, language, and EF were selected. Additionally, the study examined how a Bilingualism Index (BI) and the age of acquisition of English could predict GMV and EF in Spanish/English bilinguals whose native language was Spanish.
Lastly, the initial age of cognitive decline across language groups was compared. Results suggested higher GMV in language and EF regions in bilinguals, but differences were not found in memory regions. Furthermore, neuropsychological performance over time did not vary across language groups; however, bilinguals exhibited reduced Stroop interference as well as lower scores on Digit Span Backwards and category fluency. The age of acquisition of English did not predict GMV or EF scores, while the BI predicted category fluency, with lower scores associated with a higher degree of balanced bilingualism. Overall, the influence of bilingualism appears to be reflected in increased GMV in specific language and EF regions relative to neuropsychological performance.

The hippocampal-medial prefrontal circuit has been shown to serve a critical role
in decision making and goal directed actions. While the hippocampus (HF) exerts a direct
influence on the medial prefrontal cortex (mPFC), there are no direct return projections
from the mPFC to the HF. The nucleus reuniens (RE) of the midline thalamus is strongly
reciprocally connected with the HF and mPFC and represents the major link between
these structures.
We investigated the role of RE in functions associated with the hippocampus and
the mPFC -- or their interactions. Using two different inactivation techniques
(pharmacological and chemogenetic), we sought to further define the role of RE in spatial
working memory (SWM) and behavioral flexibility using a modified delayed non-match
to sample (DNMS) working memory task. We found that the reversible inactivation of
RE with muscimol critically impaired SWM performance, abolished well-established
spatial strategies and produced a profound inability to correct non-rewarded, incorrect choices on the T-maze (perseverative responding). We observed similar impairments in
SWM following the chemogenetic (DREADDs) inactivation of RE or selective RE
projections to the ventral HF. In addition, we showed that the inhibition of RE terminals
to the dorsal or ventral HF altered task related behaviors by increasing or decreasing the
time to initiate the task or reach the reward, respectively. Finally, we examined discharge
properties of RE cells across sleep-wake states in behaving rats. We found that the
majority of RE cells discharge at high rates of activity in waking and REM and at
significantly reduced rates in SWS, with a subpopulation firing rhythmically in bursts
during SWS. We identified five distinct subtypes of RE cells that discharged differently
across vigilant states; those firing at highest rates in waking (W1, W2), in REM sleep
(R1, R2) and SWS (S1). Given the differential patterns of activity of these cells, we
proposed they may serve distinct functions in waking – and possibly in SWS/REM sleep.
In sum, our findings indicate that RE is critically involved in mnemonic and
executive functions and the heterogeneous activity of these cells support a role for RE in
arousal/attention, spatial working memory and cognition.

Recent studies have suggested that bilingualism may provide an advantage to
older adults on inhibitory control and have a positive effect on some cognitive
declines seen in normal aging. This study examined the effects of bilingualism on
inhibitory control using a Simon task and a Stroop task on a heterogeneous sample of
bilinguals whose level of proficiency on each of their two languages varied widely.
Comparison of performances between younger and older monolingual and bilingual
participants revealed a bilingual advantage on the Simon task. Results support the
view that bilingualism increases skills that are associated with selective attention.
Additionally, older bilingual adults performed as well as younger bilingual adults
suggesting they are not experiencing the age-related declines in the efficiency of
inhibitory processes observed in the older monolingual adults. However, a bilingual
advantage was not observed on the Stroop task indicating that the advantage may
depend on the nature of the distracting stimulus. Bilinguals may be better equipped
than monolinguals at inhibiting misleading spatial information but not at inhibiting misleading linguistic information. The performance of balanced and non-balanced
bilinguals was similar under both Simon and Stroop tasks suggesting that language
level proficiency does not play a role in providing an advantage.

Two studies tested the optimality hypothesis of action identification theory (Vallacher & Wegner, 1985). This model predicts that personally difficult activities are enjoyed when they are identified in relatively low-level, "how-to" terms, whereas personally easy activities are enjoyed when they are identified in higher level, comprehensive terms. In Study 1, participants (N = 172) attempted to solve either high- or low-difficulty anagrams under various identities for their behavior. In Study 2, expert and novice artists (N = 55) drew a picture under either a high or low identity for the act of drawing. In both studies, results provided support for action identification theory's model of task enjoyment.

Man lacks the cognitive capabilities by which to process
all the complex and detailed information of the environment,
yet is able to formulate a comprehensive notion of the
environment. The present study hypothesized that a cognitive
mechanism exists by which salient information is abstracted
and stored in memory. Subjects were required to
learn to discriminate among four sets of photographs of an
urban street scene, taken from four different locations
within an area of 150 square meters. An identification
test was administered either immediately or one week after
acquisition, using photographs from the acquisition set and
novel photographs taken from the same locations but at
different camera orientations. The results indicated that
subjects abstract a continuous schematic representation from
discrete photographic samples of the total scene. These
results suggest that man in a real-world situation remembers
a general, schematic concept of the environment, rather than
detailed, specific information.

Visual average evoked potentials (AEPs) were recorded
from four male Ss in a sequential, single digit problem
solving task requiring addition of the first digit to the
second. Separate AEPs for the first and second digits
allowed Late Positive Component comparisons. It was
hypothesized that LPC latency variations are a function of
cognitive evaluation of information, with the prediction
that there would be a normal latency LPC in the first digit
AEP, where S recognizes a stimulus, as compared to a
delayed LPC in the second digit AEP where S must both
recognize and cognitively evaluate information to solve
the addition problem. Two experimental conditions, varying
stimulus presentation time between long and short, were run.
Equipment failure terminated the experiment and the
proposed study could not be researched. The pilot data
gathered were too variable and incomplete to permit conclusions.
However, these data did not contradict the hypothesis.

The purpose of this study was to determine if success in writing computer programs is related to level of cognitive development, verbal ability, math reasoning, and grade point average. This study presents a model that predicts computer programming ability. Twenty-three subjects were drawn from students enrolled in BASIC programming classes at Broward Community College. Each subject was given the School and College Ability Test (SCAT II) test to assess math and verbal levels and the Inventory of Piaget's Developmental Tasks (IPDT) to assess level of cognitive development. Grade point averages were obtained from the registrar. The instructor's final examination, which consisted of generating BASIC programs, was used as a measure of programming ability. Each student was given 45 hours of instruction in BASIC by the instructor and had access to laboratory facilities equipped with IBM Personal Computers. Pearson r correlations were performed using each predictor (grade point average, verbal ability, math reasoning, and level of cognitive development) as independent variables and computer programming ability as the dependent variable. The correlations were all significant. To determine how well all four factors together predict programming ability, multiple regression analysis was performed using all of the predictors as independent variables and computer programming ability as the dependent variable. This study supports prior research showing that grade point average, math reasoning and verbal ability were each significant predictors of success in computer programming. Results showed that level of cognitive development is linearly predictive of success in computer programming. Results of the regression showed that level of cognitive development, when combined with verbal reasoning, is linearly predictive of programming ability.