Effects of tone duration on three psychophysical measures of temporal integration in rhesus macaques

2021 ◽  
Author(s):  
Chase Mackey ◽  
Alejandro Tarabillo ◽  
Ramnarayan Ramachandran
Keyword(s):  
Process Model ◽  
Species Differences ◽  
Rhesus Macaques ◽  
Temporal Integration ◽  
Poisson Model ◽  
Detection Performance ◽  
Broadband Noise ◽  
Tone Duration ◽  
Human Data ◽  
Neurophysiological Studies

The relationship between sound duration and detection performance has long been thought to reflect temporal integration, and has been well studied in both humans and animal models. Reports of species differences are equivocal, with some metanalyses reporting no species differences, and others reporting substantial differences. This renders translational work in animals problematic. To re-evaluate this issue, tone detection performance was measured in rhesus macaques using a Go/No-Go reaction time detection task at various stimulus durations, and in the presence of broadband noise (BBN). Detection thresholds, reaction times (RT), and psychometric function slopes were calculated. All three measures were sensitive to tone duration, consistent with temporal integration. The rate of threshold change with duration was similar to human data, and was equally well fit by power law and exponential functions. The effect of tone duration on RT is the first reported in animals. BBN significantly affected how slopes changed with duration, and elevated thresholds, but did not affect how threshold or RT changed with duration. To begin investigating what processes may underlie these behavioral measures, the data were then compared to data generated using a probabilistic Poisson process model, previously compared to human data. The Poisson model recapitulated the effects of duration on threshold and psychometric slope. These behavioral data provide evidence that macaques are an exceptional model of human temporal integration, and the modeling results point the way forward for future neurophysiological studies.

scholarly journals Serial integration of sensory evidence for perceptual decisions and oculomotor responses

2020 ◽  
Author(s):  
Matteo Lisi ◽  
Michael J. Morgan ◽  
Joshua A. Solomon
Keyword(s):  
Sequential Sampling ◽  
Temporal Integration ◽  
Reverse Correlation ◽  
Decision Threshold ◽  
Response Preparation ◽  
Motor Responses ◽  
Sequential Sampling Models ◽  
Neurophysiological Studies ◽  
Oculomotor Responses ◽  
Sensory Evidence

AbstractPerceptual decisions often require the integration of noisy sensory evidence over time. This process is formalized with sequential sampling models, where evidence is accumulated up to a decision threshold before a choice is made. Although classical accounts grounded in cognitive psychology tend to consider the process of decision formation and the preparation of the motor response as occurring serially, neurophysiological studies have proposed that decision formation and response preparation occur in parallel and are inseparable (Cisek, 2007; Shadlen et al., 2008). To address this serial vs. parallel debate, we developed a behavioural, reverse correlation protocol, in which the stimuli that influence perceptual decisions can be distinguished from the stimuli that influence motor responses. We show that the temporal integration windows supporting these two processes are distinct and largely non-overlapping, suggesting that they proceed in a serial or cascaded fashion.

scholarly journals Capuchin and rhesus monkeys but not humans show cognitive flexibility in an optional-switch task

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Julia Watzek ◽  
Sarah M. Pope ◽  
Sarah F. Brosnan
Keyword(s):  
Working Memory ◽  
Cognitive Flexibility ◽  
Relative Efficiency ◽  
Rhesus Monkeys ◽  
Species Differences ◽  
Rhesus Macaques ◽  
Capuchin Monkeys ◽  
Cognitive Set ◽  
Strategy Versus

Abstract Learned rules help us accurately solve many problems, but by blindly following a strategy, we sometimes fail to find more efficient alternatives. Previous research found that humans are more susceptible to this “cognitive set” bias than other primates in a nonverbal computer task. We modified the task to test one hypothesis for this difference, that working memory influences the advantage of taking a shortcut. During training, 60 humans, 7 rhesus macaques, and 22 capuchin monkeys learned to select three icons in sequence. They then completed 96 baseline trials, in which only this learned rule could be used, and 96 probe trials, in which they could also immediately select the final icon. Rhesus and capuchin monkeys took this shortcut significantly more often than humans. Humans used the shortcut more in this new, easier task than in previous work, but started using it significantly later than the monkeys. Some participants of each species also used an intermediate strategy; they began the learned rule but switched to the shortcut after selecting the first item in the sequence. We suggest that these species differences arise from differences in rule encoding and in the relative efficiency of exploiting a familiar strategy versus exploring alternatives.

Temporal Integration of the Contralateral Acoustic Reflex Threshold for a 1000 Hz Tonal Activator and Its Age-Related Changes

2009 ◽  
Vol 20 (04) ◽  
pp. 225-228 ◽  
Author(s):  
Michele B. Emmer ◽  
Shlomo Silman ◽  
Carol A. Silverman ◽  
Harry Levitt
Keyword(s):  
Temporal Integration ◽  
Age Effect ◽  
Broadband Noise ◽  
Hearing Level ◽  
Acoustic Reflex ◽  
Hearing Sensitivity ◽  
Age Related ◽  
Main Effect ◽  
Reflex Threshold ◽  
Acoustic Reflex Threshold

Background: Previous research has noted an age effect on the temporal integration of the acoustic reflex for a noise activator. Purpose: To determine whether the age effect earlier noted for a noise activator will be noted for a tonal activator. Research Design: Comparison of ARTs of younger and older groups at activating stimulus durations of 12, 25, 50, 100, 200, 300, 500, and 1000 msec. Study Sample: Two groups of adults with normal-hearing sensitivity: one group of 20 young adults (ten males and ten females, ages 18–29 years, with a mean age of 24 years) and one group of 20 older adults (ten males and ten females, ages 59–75 years, with a mean age of 67.5 years). Results: A significant main effect for duration was obtained. That is, as the duration increased, the acoustic reflex threshold for the 1000 Hz tonal activator decreased. The interactions of duration × age group and duration × hearing level were not significant. There was a nonsignificant main effect (p = .889) for the between-subjects factor of age. Conclusion: Results contradict the findings for broadband noise.

Choice-related activity and neural encoding in primary auditory cortex and lateral belt during feature selective attention

2021 ◽  
Author(s):  
Jennifer Leigh Mohn ◽  
Joshua D Downer ◽  
Kevin N. O'Connor ◽  
Jeffrey Scott Johnson ◽  
Mitchell L Sutter
Keyword(s):  
Selective Attention ◽  
Auditory Cortex ◽  
Rhesus Macaques ◽  
Primary Auditory Cortex ◽  
Motor Preparation ◽  
Broadband Noise ◽  
Neural Encoding ◽  
Related Activity ◽  
Attention Task ◽  
The Relationship

Selective attention is necessary to sift through, form a coherent percept of, and make behavioral decisions on the vast amount of information present in most sensory environments. How and where selective attention is employed in cortex and how this perceptual information then informs the relevant behavioral decisions is still not well understood. Studies probing selective attention and decision making in visual cortex have been enlightening as to how sensory attention might work in that modality; whether or not similar mechanisms are employed in auditory attention is not yet clear. Therefore, we trained rhesus macaques on a feature selective attention task, where they switched between reporting changes in temporal (amplitude modulation, AM) and spectral (carrier bandwidth) features of a broadband noise stimulus. We investigated how the encoding of these features by single neurons in primary (A1) and secondary (middle lateral belt, ML) auditory cortex were affected by the different attention conditions. We found that neurons in A1 and ML showed mixed-selectivity to the sound and task features. We found no difference in AM encoding between the attention conditions. We found that choice-related activity in both A1 and ML neurons shifts between attentional conditions. This finding suggests that choice-related activity in auditory cortex does not simply reflect motor preparation or action, and supports the relationship between reported choice-related activity and the decision and perceptual process.

scholarly journals Amplitude Modulation detection ability can be differentially affected using state-dependent Transcranial Magnetic Stimulation

2017 ◽  
Author(s):  
Adam Michael Partridge ◽  
Garreth Prendergast ◽  
Mark Hymers
Keyword(s):  
Amplitude Modulation ◽  
Auditory Processing ◽  
Right Hemisphere ◽  
Temporal Integration ◽  
Broadband Noise ◽  
Detection Ability ◽  
Behavioural Adaptation ◽  
State Dependent ◽  
Left And Right ◽  
Auditory Cortices

Temporal changes in the speech envelope are crucial for intelligibility, and humans are particularly sensitive to amplitude modulations (AM) at frequencies commensurate with the syllabic rate (4Hz). Some asymmetric models of auditory processing have attempted to explain observed functional asymmetries between left and right auditory cortices in terms of temporal integration windows of differing lengths. In this paper we use an fMRI-localised, state-dependent, dual-pulse TMS paradigm to investigate auditory processing as exemplified by detection of sinusoidal amplitude modulation of a broadband noise carrier. The effect of left and right hemisphere TMS on accuracy levels for detection of such modulations at rates of 4 and 40Hz under conditions of behavioural adaptation were examined. Effects of TMS on AM detection were found only in the 40Hz detection task when TMS was applied to the left hemisphere. Further, this effect showed a dissociation based on the modulation used during behavioural adaptation, with a facilitation shown when participants were behaviourally adapted to 4Hz AM whereas a disruption was shown when participants were behaviourally adapted to 40Hz AM, contrary to initial predictions based on state-dependent TMS theory. These results show for the first time that it is possible to differentially affect AM detection ability using TMS and further emphasise the importance of subtle timing factors in TMS studies. The novel use of this technique in the auditory domain has implications for further elucidating auditory processing mechanisms in health and disease.

scholarly journals frenchFISH: Poisson models for quantifying DNA copy-number from fluorescence in situ hybridisation of tissue sections

2018 ◽  
Author(s):  
Geoff Macintyre ◽  
Anna M Piskorz ◽  
Edith Ross ◽  
David B Morse ◽  
Ke Yuan ◽  
...  
Keyword(s):  
Copy Number ◽  
Process Model ◽  
In Situ Hybridisation ◽  
Poisson Model ◽  
Correction Method ◽  
Fluorescence In Situ Hybridisation ◽  
Dna Copy Number ◽  
Tissue Sections ◽  
Poisson Models

Chromosomal aberration and DNA copy number change are robust hallmarks of cancer. Imaging of spots generated using fluorescence in situ hybridisation (FISH) of locus specific probes is routinely used to detect copy number changes in tumour nuclei. However, it often does not perform well on solid tumour tissue sections, where partially represented or overlapping nuclei are common. To overcome these challenges, we have developed a computational approach called FrenchFISH, which comprises a nuclear volume correction method coupled with two types of Poisson models: either a Poisson model for improved manual spot counting without the need for control probes; or a homogenous Poisson Point Process model for automated spot counting. We benchmarked the performance of FrenchFISH against previous approaches in a controlled simulation scenario and exemplify its use in 12 ovarian cancer FFPE-tissue sections, for which we assess copy number alterations in three loci (c-Myc, hTERC and SE7). We show that FrenchFISH outperforms standard spot counting approaches and that the automated spot counting is significantly faster than manual without loss of performance. FrenchFISH is a general approach that can be used to enhance clinical diagnosis on sections of any tissue.

scholarly journals Hierarchical effects of choice-related activity and neural encoding during feature selective attention

2020 ◽  
Author(s):  
Jennifer L. Mohn ◽  
Joshua D. Downer ◽  
Kevin N. O’Connor ◽  
Jeffrey S. Johnson ◽  
Mitchell L. Sutter
Keyword(s):  
Selective Attention ◽  
Auditory Cortex ◽  
Rhesus Macaques ◽  
Motor Preparation ◽  
Broadband Noise ◽  
Single Neurons ◽  
Neural Encoding ◽  
Related Activity ◽  
Attention Task ◽  
The Relationship

AbstractSelective attention is necessary to sift through, form a coherent percept of, and make behavioral decisions on the vast amount of information present in most sensory environments. How and where selective attention is employed in cortex and how this perceptual information then informs the relevant behavioral decisions is still not well understood. Studies probing selective attention and decision making in visual cortex have been enlightening as to how sensory attention might work in that modality; whether or not similar mechanisms are employed in auditory attention is not yet clear. Therefore, we trained rhesus macaques on a feature selective attention task, where they switched between reporting changes in temporal (amplitude modulation, AM) and spectral (carrier bandwidth) features of a broadband noise stimulus. We investigated how the encoding of these features by single neurons in primary (A1) and secondary (lateral belt, ML) auditory cortex were affected by the different attention conditions. We found that neurons in A1 and ML showed mixed-selectivity to the sound and task features. We found no difference in AM encoding between the attention conditions. We found that choice-related activity in both A1 and ML neurons shifts between attentional conditions. This finding suggests that choice-related activity in auditory cortex does not simply reflect motor preparation or action, and supports the relationship between reported choice-related activity and the decision and perceptual process.New & NoteworthyWe recorded from primary and secondary auditory cortex while monkeys performed a non-spatial feature attention task. Both areas exhibited rate-based choice-related activity. The manifestation of choice-related activity was attention-dependent, suggesting that choice-related activity in auditory cortex does not simply reflect arousal or motor influences, but relates to the specific perceptual choice. The lack of temporal-based choice activity is consistent with growing evidence that subcortical, but not cortical, single neurons inform decisions through temporal envelope following.

scholarly journals FrenchFISH: Poisson Models for Quantifying DNA Copy Number From Fluorescence In Situ Hybridization of Tissue Sections

2021 ◽  
pp. 176-186
Author(s):  
Geoff Macintyre ◽  
Anna M. Piskorz ◽  
Adam Berman ◽  
Edith Ross ◽  
David B. Morse ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Copy Number ◽  
Process Model ◽  
Poisson Model ◽  
Correction Method ◽  
Dna Copy Number ◽  
Tissue Sections ◽  
Poisson Models

PURPOSE Chromosomal aberration and DNA copy number change are robust hallmarks of cancer. The gold standard for detecting copy number changes in tumor cells is fluorescence in situ hybridization (FISH) using locus-specific probes that are imaged as fluorescent spots. However, spot counting often does not perform well on solid tumor tissue sections due to partially represented or overlapping nuclei. MATERIALS AND METHODS To overcome these challenges, we have developed a computational approach called FrenchFISH, which comprises a nuclear volume correction method coupled with two types of Poisson models: either a Poisson model for improved manual spot counting without the need for control probes or a homogeneous Poisson point process model for automated spot counting. RESULTS We benchmarked the performance of FrenchFISH against previous approaches using a controlled simulation scenario and tested it experimentally in 12 ovarian carcinoma FFPE-tissue sections for copy number alterations at three loci (c-Myc, hTERC, and SE7). FrenchFISH outperformed standard spot counting with 74% of the automated counts having < 1 copy number difference from the manual counts and 17% having < 2 copy number differences, while taking less than one third of the time of manual counting. CONCLUSION FrenchFISH is a general approach that can be used to enhance clinical diagnosis on sections of any tissue by both speeding up and improving the accuracy of spot count estimates.

scholarly journals Intrusion detection by machine learning = Behatolás detektálás gépi tanulás által

2020 ◽  
Author(s):  
◽  
Csaba Brunner
Keyword(s):  
Machine Learning ◽  
Information Technology ◽  
Intrusion Detection ◽  
Process Model ◽  
Detection Performance ◽  
Learning Models ◽  
Detection Techniques ◽  
Network Intrusion ◽  
Hybrid Detection ◽  
Machine Learning Models

Since the early days of information technology, there have been many stakeholders who used the technological capabilities for their own benefit, be it legal operations, or illegal access to computational assets and sensitive information. Every year, businesses invest large amounts of effort into upgrading their IT infrastructure, yet, even today, they are unprepared to protect their most valuable assets: data and knowledge. This lack of protection was the main reason for the creation of this dissertation. During this study, intrusion detection, a field of information security, is evaluated through the use of several machine learning models performing signature and hybrid detection. This is a challenging field, mainly due to the high velocity and imbalanced nature of network traffic. To construct machine learning models capable of intrusion detection, the applied methodologies were the CRISP-DM process model designed to help data scientists with the planning, creation and integration of machine learning models into a business information infrastructure, and design science research interested in answering research questions with information technology artefacts. The two methodologies have a lot in common, which is further elaborated in the study. The goals of this dissertation were two-fold: first, to create an intrusion detector that could provide a high level of intrusion detection performance measured using accuracy and recall and second, to identify potential techniques that can increase intrusion detection performance. Out of the designed models, a hybrid autoencoder + stacking neural network model managed to achieve detection performance comparable to the best models that appeared in the related literature, with good detections on minority classes. To achieve this result, the techniques identified were synthetic sampling, advanced hyperparameter optimization, model ensembles and autoencoder networks. In addition, the dissertation set up a soft hierarchy among the different detection techniques in terms of performance and provides a brief outlook on potential future practical applications of network intrusion detection models as well.

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