486,626 research outputs found
Lack of associations between female hormone levels and visuospatial working memory, divided attention and cognitive bias across two consecutive menstrual cycles
Background: Interpretation of observational studies on associations between prefrontal cognitive functioning and hormone levels across the female menstrual cycle is complicated due to small sample sizes and poor replicability. Methods: This observational multisite study comprised data of n = 88 menstruating women from Hannover, Germany, and Zurich, Switzerland, assessed during a first cycle and n = 68 re-assessed during a second cycle to rule out practice effects and false-positive chance findings. We assessed visuospatial working memory, attention, cognitive bias and hormone levels at four consecutive time-points across both cycles. In addition to inter-individual differences we examined intra-individual change over time (i.e., within-subject effects). Results: Estrogen, progesterone and testosterone did not relate to inter-individual differences in cognitive functioning. There was a significant negative association between intra-individual change in progesterone and change in working memory from pre-ovulatory to mid-luteal phase during the first cycle, but that association did not replicate in the second cycle. Intra-individual change in testosterone related negatively to change in cognitive bias from menstrual to pre-ovulatory as well as from pre-ovulatory to mid-luteal phase in the first cycle, but these associations did not replicate in the second cycle. Conclusions: There is no consistent association between women’s hormone levels, in particular estrogen and progesterone, and attention, working memory and cognitive bias. That is, anecdotal findings observed during the first cycle did not replicate in the second cycle, suggesting that these are false-positives attributable to random variation and systematic biases such as practice effects. Due to methodological limitations, positive findings in the published literature must be interpreted with reservation
Cognitive computing meets the internet of things
Abstract: This paper discusses the blend of cognitive computing with the Internet-of-Things that should result into developing cognitive things. Today’s things are confined into a data-supplier role, which deprives them from being the technology of choice for smart applications development. Cognitive computing is about reasoning, learning, explaining, acting, etc. In this paper, cognitive things’ features include functional and non-functional restrictions along with a 3 stage operation cycle that takes into account these restrictions during reasoning, adaptation, and learning. Some implementation details about cognitive things are included in this paper based on a water pipe case-study
The Timing of the Cognitive Cycle
We propose that human cognition consists of cascading cycles of recurring brain
events. Each cognitive cycle senses the current situation, interprets it with
reference to ongoing goals, and then selects an internal or external action in
response. While most aspects of the cognitive cycle are unconscious, each cycle
also yields a momentary “ignition” of conscious broadcasting.
Neuroscientists have independently proposed ideas similar to the cognitive
cycle, the fundamental hypothesis of the LIDA model of cognition. High-level
cognition, such as deliberation, planning, etc., is typically enabled by
multiple cognitive cycles. In this paper we describe a timing model LIDA's
cognitive cycle. Based on empirical and simulation data we propose that an
initial phase of perception (stimulus recognition) occurs 80–100 ms from
stimulus onset under optimal conditions. It is followed by a conscious episode
(broadcast) 200–280 ms after stimulus onset, and an action selection phase
60–110 ms from the start of the conscious phase. One cognitive cycle would
therefore take 260–390 ms. The LIDA timing model is consistent with brain
evidence indicating a fundamental role for a theta-gamma wave, spreading forward
from sensory cortices to rostral corticothalamic regions. This posteriofrontal
theta-gamma wave may be experienced as a conscious perceptual event starting at
200–280 ms post stimulus. The action selection component of the cycle is
proposed to involve frontal, striatal and cerebellar regions. Thus the cycle is
inherently recurrent, as the anatomy of the thalamocortical system suggests. The
LIDA model fits a large body of cognitive and neuroscientific evidence. Finally,
we describe two LIDA-based software agents: the LIDA Reaction Time agent that
simulates human performance in a simple reaction time task, and the LIDA Allport
agent which models phenomenal simultaneity within timeframes comparable to human
subjects. While there are many models of reaction time performance, these
results fall naturally out of a biologically and computationally plausible
cognitive architecture
The Role of Early-Life Conditions in the Cognitive Decline due to Adverse Events Later in Life
Cognitive functioning of elderly individuals may be affected by events such as the loss of a (grand)child or partner or the onset of a serious chronic condition, and by negative economic shocks such as job loss or the reduction of pension benefits. It is conceivable that the impact of such events is stronger if conditions early in life were adverse. In this paper we address this using a Dutch longitudinal database that follows elderly individuals for more than 15 years and contains information on demographics, socio-economic conditions, life events, health, and cognitive functioning. We exploit exogenous variation in early-life conditions as generated by the business cycle. We also examine to what extent the cumulative effect of consecutive shocks later in life exceeds the sum of the separate effects, and whether economic and health shocks later in life reinforce each other in their effect on cognitive functioning.cognitive functioning, business cycle, bereavement, developmental origins, retirement, health, long-run effects, dementia
Signal Detection for QPSK Based Cognitive Radio Systems using Support Vector Machines
Cognitive radio based network enables opportunistic dynamic spectrum access by sensing, adopting and utilizing the unused portion of licensed spectrum bands. Cognitive radio is intelligent enough to adapt the communication parameters of the unused licensed spectrum. Spectrum sensing is one of the most important tasks of the cognitive radio cycle. In this paper, the auto-correlation function kernel based Support Vector Machine (SVM) classifier along with Welch's Periodogram detector is successfully implemented for the detection of four QPSK (Quadrature Phase Shift Keying) based signals propagating through an AWGN (Additive White Gaussian Noise) channel. It is shown that the combination of statistical signal processing and machine learning concepts improve the spectrum sensing process and spectrum sensing is possible even at low Signal to Noise Ratio (SNR) values up to -50 dB
The effect of early cognitive ability on earnings over the life-cycle
This paper utilizes information on cognitive ability at age ten and earnings information from age 20 to 65 to estimate the return to ability over the life-cycle. Ability measured at an early age is not influenced by the individual’s choices of schooling and other circumstances. We find that most of the unconditional return to early cognitive ability goes through educational choice. The conditional return is increasing for low levels of experience and non-increasing for experience above about 15-25 years. The return is similar for men and women, and highest for individuals with academic education. Only a small part of the return can be explained by higher probability to have a supervisory position.Cognitive ability; life-cycle; earnings; IQ
Applications of Cognitive Radio Networks
The term cognitive radio (CR), originally coined in the late 1990s, envisaged a radio that is aware of its operational environment so that it can dynamically and autonomously adjust its radio-operating parameters to accordingly adapt to the different situations. Cognition is achieved through the so-called cognitive cycle, consisting of the observation of the environment, the orientation and planning that leads to making appropriate decisions in accordance with specific operation goals, and finally, the execution of these decisions (e.g., access to the appropriate channel). Decisions can be reinforced by learning procedures based on the past observations and the corresponding results of prior actuations
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