Heart-Rate Responses and Hebb-Williams Maze Performance in Three Different Age Groups of Rats

1980 ◽  
Vol 46 (1) ◽  
pp. 331-338
Author(s):  
A. Ivinskis

A study was carried out to examine heart-rate changes and changes in performance levels in Hebb-Williams maze in three different age groups of rats (21, 43, and 83 days old). Heart rate was recorded using a miniature FM radio transmitter. The rats were first exposed to 6 odd Hebb-Williams maze items and were retested 12 days later using 6 even test items. The main findings were: over-all the heart rate was significantly higher in the 21-day-old group and heart rate in this group decreased during the running of the maze while it increased in the other two groups. Heart-rate responses increased as a function of trials in all the groups and increased most sharply for the 21-day-old group. On retest a significant over-all decrease occurred in the heart-rate responses. The short-term reliability of heart rate was quite high for all the age groups. The 21-day-old group rats made significantly fewer errors in the Hebb-Williams maze when compared with the two older groups but the test-retest reliability of the Hebb-Williams maze scores was very low in the 21-day group relative to the other two. The results are discussed in terms of response inhibition and changes in drive level as a function of age. Questions are also raised concerning the validity of the Hebb-Williams maze test as a measure of problem-solving behavior.

2022 ◽  
Vol 50 ◽  
Author(s):  
Luciene Maria Martinello Romão ◽  
Amanda Sarita Cruz Aleixo ◽  
Felipe Gazza Romão ◽  
Mayra De Castro Ferreira Lima ◽  
Miriam Tsunemi ◽  
...  

Background: The modulation of heart rate by autonomic nervous system may be evaluated by the heart rate variability (HRV), which illustrates the fluctuations between RR intervals. To evaluate this analysis, the intervals between 2 QRS complexes are measured. In general, high HRV values are expected in healthy individuals; otherwise, low values are indicative of organism dysfunction. Studies conducted in healthy humans show that HRV suffers reduction with ageing and that there is autonomic immaturity in neonates. The aim of this study was to describe the characteristic pattern of cardiac autonomic behavior in healthy dogs in different age groups through short-term HRV analysis.Materials, Methods & Results: A total of 87 healthy dogs were studied. HRV was analyzed in time and frequency domain, using Holter and heart rate monitor. It was observed that puppies (below one year old) presented a lower parasympathetic predominance and, consequently, lower HRV values on time domain (SDNN, PNN50% e RMSSD) compared to the other 2 groups and on frequency domain (LF, HF and LF/HF) compared to the adult animals group (between 1 and 7-year-old), which presented higher HRV values when compared to the other groups. Elderly dogs (over 8-year-old) exhibited a natural tendency to decrease cardiac parasympathetic HRV indexes.Discussion: The use of the HRV method as a prognostic index and as an arrhythmogenic marker for various canine heart diseases presents interesting perspectives. However, before it may be employed for these purposes, a better understanding should be established regarding the physiological behavior of autonomic cardiac modulation in different age groups to serve as a basis for future analyses. This study observed that puppies presented higher values for HR and, therefore, shorter RR intervals than the other groups (adult and elderly dogs), what was observed on Holter and heart rate monitor methods (HRM). There were significant differences between puppies and the other 2 groups (adults and elderly) for all time-domain variables using both methods (Holter and HRM methods). SDNN was significantly lower in puppies compared to adults and elderly dogs. In addition, both RMSSD and PNN50%, which were more reliable over shorter periods of time, also presented means and medians that were significantly lower in puppies. Regarding frequency-domain HRV parameters observed on Holter method, these indexes were decreased on the elderly group compared to adult dogs, which is a possible effect of aging. Also, puppies revealed lower frequency-domain HRV parameters on both methods when compared to adult dogs. The influence of age on HRV is possibly related to the stage of development of an individual, starting at conception up to the maturity in relation to the mechanisms that cause variations in HR. There are studies in humans that suggest a gradual increase in parasympathetic activity during childhood, followed by a steady decrease as aging occur. The present study observed the same pattern in dogs. The balance between sympathetic and parasympathetic systems is influenced by age in dogs, which alters HRV values in the short-term. The HRV method´s analysis is relatively simple and non-invasive for assessing cardiac autonomic function; also, it is widely used in human medicine as a risk measure for sudden cardiac death. The 24-hour HRV analysis is highly challenging, as it is time-consuming, expensive, delays diagnosis, and has a large number of artifacts; in this way, standards for its short-term analysis were developed. Keywords: cardiology, autonomic nervous system, heart rate monitor, Holter.


2014 ◽  
Vol 23 (3-4) ◽  
pp. 151-168
Author(s):  
Aristotelis Gioldasis ◽  
Evangelos Bekris ◽  
Ioannis Gissis

Abstract The aim of this study was to examine the anthropometric and fitness characteristics of soccer players with different positional role. Although, players’ skills are not equally distributed in each position, at elite soccer they have to perform each skill at a sufficient level. However, coaches expertise those from an early age in specific positions without giving them an holistic individualized training. In the study participated 312 Greek players aged 6 to 17 (M= 11.89; SD= 2.33) of 5 age groups (group U7-U8; group U9-U10; group U11-U12; group U13-U14; group U15-U16; group U17). Anthropometric (height, weight, body mass index and body fat) and fitness characteristics (flexibility, vertical jump, running speed, agility and VO2max) of participants were measured. The study showed that goalkeepers and central defenders tend to perform worse than players of the other positional groups in most of their fitness characteristics for almost all the age groups. Furthermore, many tendencies were observed in anthropometric and fitness characteristics between players with different positional roles. This study provides suggestions to coaches regarding their practice of positioning players according to their anthropometric and fitness characteristics for a short term success.


2020 ◽  
Vol 9 (11) ◽  
pp. 3537
Author(s):  
Maria D. Alvarez-Bermudez ◽  
Flores Martin-Reyes ◽  
Luis Ocaña-Wilhelmi ◽  
Francisco J. Moreno-Ruiz ◽  
Juan Alcaide Torres ◽  
...  

Background The percentage of excess weight lost (%EWL) after bariatric surgery (BS) shows great discrepancies from one individual to another. Objective To evaluate the %EWL one year after BS and to determine the existence of baseline biomarkers associated with weight loss. Methods We studied 329 patients with morbid obesity undergoing three types of BS (biliopancreatic diversion (BPD), Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG)), depending on the %EWL one year after surgery: good responders (GR) (%EWL ≥ 50%) and non-responders (NR) (%EWL < 50%). Results The GR presented a higher percentage of change in anthropometric and biochemical variables compared to the NR group, even within each type of BS. There was a greater percentage of GR among those who underwent RYGB. The patients who underwent SG showed the lowest decrease in biochemical variables, both in GR and NR. Within the GR group, those with a lower age showed greater improvement compared to the other age groups. A %EWL ≥50% was negatively associated with the age and atherogenic index of plasma (AIP), and positively with the type of BS (RYGB). Conclusions The GR group was associated with lower age and AIP and undergoing RYGB. Additionally, those patients who underwent SG showed a lower metabolic improvement.


Author(s):  
Kang-Ming Chang ◽  
Miao-Tien Wu Chueh ◽  
Yi-Jung Lai

Background: It is well known that meditation improves the physical and psychological condition of its practitioners. This study investigated the heart rate variability response of meditation practitioners in two Chan master teaching environments, namely face-to-face and video classes. Methods: Experimental sessions were conducted, one featuring face-to-face classes and the other featuring video classes. The difference in participants’ physiological parameters (blood pressure and heart rate variability) between the two experimental sessions was determined. In the first session, physiological parameters were recorded twice, before and after one teaching course, and the second session took place one month after the first. The first and second sessions had 45 and 27 participants, respectively. Those involved in the first experiment had no experience with meditation, whereas participants in the second experiment had practiced meditation for an average of 9 years (range = 1 to 27 years). Both experiments were conducted once a week, with each session lasting 1.5 h. Results: For both experiments, both heart rate and heart rate variability by age significantly decreased after one teaching course. Conclusions: Chan meditation practitioners benefit from receiving both face-to-face and video class teaching from a Chan master.


2019 ◽  
Vol 7 ◽  
Author(s):  
Galya Nikolova Georgieva-Tsaneva

The physiological signals that are recorded from different parts of the human body have a non-stationary nature and the tracking of their dynamics is an interesting research problem. This report examines Heart Rate Variability through the use of statistical methods of analysis that are traditionally used to study the functionality of the heart and via Detrended Fluctuation Analysis. The use of the technique of Detrended Fluctuation Analysis allows the investigation of short-term and long-term correlations in non-stationary Heart Rate Variability series. A study has been made of the changes in the functioning of the human heart, depending on the age. The study encompasses healthy individuals in three different age groups. The analysis of the obtained results shows a change in the correlated behavior of the investigated signals with an increase in age.


2000 ◽  
Vol 16 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Hans Ottosson ◽  
Martin Grann ◽  
Gunnar Kullgren

Summary: Short-term stability or test-retest reliability of self-reported personality traits is likely to be biased if the respondent is affected by a depressive or anxiety state. However, in some studies, DSM-oriented self-reported instruments have proved to be reasonably stable in the short term, regardless of co-occurring depressive or anxiety disorders. In the present study, we examined the short-term test-retest reliability of a new self-report questionnaire for personality disorder diagnosis (DIP-Q) on a clinical sample of 30 individuals, having either a depressive, an anxiety, or no axis-I disorder. Test-retest scorings from subjects with depressive disorders were mostly unstable, with a significant change in fulfilled criteria between entry and retest for three out of ten personality disorders: borderline, avoidant and obsessive-compulsive personality disorder. Scorings from subjects with anxiety disorders were unstable only for cluster C and dependent personality disorder items. In the absence of co-morbid depressive or anxiety disorders, mean dimensional scores of DIP-Q showed no significant differences between entry and retest. Overall, the effect from state on trait scorings was moderate, and it is concluded that test-retest reliability for DIP-Q is acceptable.


2012 ◽  
Vol 17 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Rosalind Potts ◽  
Robin Law ◽  
John F. Golding ◽  
David Groome

Retrieval-induced forgetting (RIF) refers to the finding that the retrieval of an item from memory impairs the retrieval of related items. The extent to which this impairment is found in laboratory tests varies between individuals, and recent studies have reported an association between individual differences in the strength of the RIF effect and other cognitive and clinical factors. The present study investigated the reliability of these individual differences in the RIF effect. A RIF task was administered to the same individuals on two occasions (sessions T1 and T2), one week apart. For Experiments 1 and 2 the final retrieval test at each session made use of a category-cue procedure, whereas Experiment 3 employed category-plus-letter cues, and Experiment 4 used a recognition test. In Experiment 2 the same test items that were studied, practiced, and tested at T1 were also studied, practiced, and tested at T2, but for the remaining three experiments two different item sets were used at T1 and T2. A significant RIF effect was found in all four experiments. A significant correlation was found between RIF scores at T1 and T2 in Experiment 2, but for the other three experiments the correlations between RIF scores at T1 and T2 failed to reach significance. This study therefore failed to find clear evidence for reliable individual differences in RIF performance, except where the same test materials were used for both test sessions. These findings have important implications for studies involving individual differences in RIF performance.


Author(s):  
Stefan Scherbaum ◽  
Simon Frisch ◽  
Maja Dshemuchadse

Abstract. Folk wisdom tells us that additional time to make a decision helps us to refrain from the first impulse to take the bird in the hand. However, the question why the time to decide plays an important role is still unanswered. Here we distinguish two explanations, one based on a bias in value accumulation that has to be overcome with time, the other based on cognitive control processes that need time to set in. In an intertemporal decision task, we use mouse tracking to study participants’ responses to options’ values and delays which were presented sequentially. We find that the information about options’ delays does indeed lead to an immediate bias that is controlled afterwards, matching the prediction of control processes needed to counter initial impulses. Hence, by using a dynamic measure, we provide insight into the processes underlying short-term oriented choices in intertemporal decision making.


2018 ◽  
pp. 49-68 ◽  
Author(s):  
M. E. Mamonov

Our analysis documents that the existence of hidden “holes” in the capital of not yet failed banks - while creating intertemporal pressure on the actual level of capital - leads to changing of maturity of loans supplied rather than to contracting of their volume. Long-term loans decrease, whereas short-term loans rise - and, what is most remarkably, by approximately the same amounts. Standardly, the higher the maturity of loans the higher the credit risk and, thus, the more loan loss reserves (LLP) banks are forced to create, increasing the pressure on capital. Banks that already hide “holes” in the capital, but have not yet faced with license withdrawal, must possess strong incentives to shorten the maturity of supplied loans. On the one hand, it raises the turnovers of LLP and facilitates the flexibility of capital management; on the other hand, it allows increasing the speed of shifting of attracted deposits to loans to related parties in domestic or foreign jurisdictions. This enlarges the potential size of ex post revealed “hole” in the capital and, therefore, allows us to assume that not every loan might be viewed as a good for the economy: excessive short-term and insufficient long-term loans can produce the source for future losses.


Sign in / Sign up

Export Citation Format

Share Document