Horizontal Head Movements Research Articles

A Pilot Study of Horizontal Head and Eye Rotations in Baseball Batting.

The purpose of the study was to measure and compare horizontal head and eye tracking movements as baseball batters "took" pitches and swung at baseball pitches. Two former college baseball players were tested in two conditions. A pitching machine was used to project tennis balls toward the subjects. In the first condition, subjects acted as if they were taking (i.e., not swinging) the pitches. In the second condition, subjects attempted to bat the pitched balls. Head movements were measured with an inertial sensor; eye movements were measured with a video eye tracker. For each condition, the relationship between the horizontal head and eye rotations was similar for the two subjects, as were the overall head-, eye-, and gaze-tracking strategies. In the "take" condition, head movements in the direction of the ball were larger than eye movements for much of the pitch trajectory. Large eye movements occurred only late in the pitch trajectory. Gaze was directed near the ball until approximately 150 milliseconds before the ball arrived at the batter, at which time gaze was directed ahead of the ball to a location near that occupied when the ball crosses the plate. In the "swing" condition, head movements in the direction of the ball were larger than eye movements throughout the pitch trajectory. Gaze was directed near the ball until approximately 50 to 60 milliseconds prior to pitch arrival at the batter. Horizontal head rotations were larger than horizontal eye rotations in both the "take" and "swing" conditions. Gaze was directed ahead of the ball late in the pitch trajectory in the "take" condition, whereas gaze was directed near the ball throughout much of the pitch trajectory in the "swing" condition.

Functional Organization of Vestibulo-Ocular Responses in Abducens Motoneurons.

Vestibulo-ocular reflexes (VORs) are the dominating contributors to gaze stabilization in all vertebrates. During horizontal head movements, abducens motoneurons form the final element of the reflex arc that integrates visuovestibular inputs into temporally precise motor commands for the lateral rectus eye muscle. Here, we studied a possible differentiation of abducens motoneurons into subtypes by evaluating their morphology, discharge properties, and synaptic pharmacology in semi-intact in vitro preparations of larval Xenopus laevis Extracellular nerve recordings during sinusoidal head motion revealed a continuum of resting rates and activation thresholds during vestibular stimulation. Differences in the sensitivity to changing stimulus frequencies and velocities allowed subdividing abducens motoneurons into two subgroups, one encoding the frequency and velocity of head motion (Group I), and the other precisely encoding angular velocity independent of stimulus frequency (Group II). Computational modeling indicated that Group II motoneurons are the major contributor to actual eye movements over the tested stimulus range. The segregation into two functional subgroups coincides with a differential activation of glutamate receptor subtypes. Vestibular excitatory inputs in Group I motoneurons are mediated predominantly by NMDA receptors and to a lesser extent by AMPA receptors, whereas an AMPA receptor-mediated excitation prevails in Group II motoneurons. Furthermore, glycinergic ipsilateral vestibular inhibitory inputs are activated during the horizontal VOR, whereas the tonic GABAergic inhibition is presumably of extravestibular origin. These findings support the presence of physiologically and pharmacologically distinct functional subgroups of extraocular motoneurons that act in concert to mediate the large dynamic range of extraocular motor commands during gaze stabilization.SIGNIFICANCE STATEMENT Outward-directed gaze-stabilizing eye movements are commanded by abducens motoneurons that combine different sensory inputs including signals from the vestibular system about ongoing head movements (vestibulo-ocular reflex). Using an amphibian model, this study investigates whether different types of abducens motoneurons exist that become active during different types of eye movements. The outcome of this study demonstrates the presence of specific motoneuronal populations with pharmacological profiles that match their response dynamics. The evolutionary conservation of the vestibulo-ocular circuitry makes it likely that a similar motoneuronal organization is also implemented in other vertebrates. Accordingly, the physiological and pharmacological understanding of specific motoneuronal contributions to eye movements might help in designing drug therapies for human eye movement dysfunctions such as abducens nerve palsy.

Dynamic perspective cues enhance depth perception from motion parallax.

Motion parallax, the perception of depth resulting from an observer's self-movement, has almost always been studied with random dot textures in simplified orthographic rendering. Here we examine depth from motion parallax in more naturalistic conditions using textures with an overall 1/f spectrum and dynamic perspective rendering. We compared depth perception for orthographic and perspective rendering, using textures composed of two types of elements: random dots and Gabor micropatterns. Relative texture motion (shearing) with square wave corrugation patterns was synchronized to horizontal head movement. Four observers performed a two-alternative forced choice depth ordering task with monocular viewing, in which they reported which part of the texture appeared in front of the other. For both textures, depth perception was better with dynamic perspective than with orthographic rendering, particularly at larger depths. Depth ordering performance with naturalistic 1/f textures was slightly lower than with the random dots; however, with depth-related size scaling of the micropatterns, performance was comparable to that with random dots. We also examined the effects of removing each of the three cues that distinguish dynamic perspective from orthographic rendering: (a) small vertical displacements, (b) lateral gradients of speed across the corrugations, and (c) speed differences in rendered near versus far surfaces. Removal of any of the three cues impaired performance. In conclusion, depth ordering performance is enhanced by all of the dynamic perspective cues but not by using more naturalistic 1/f textures.

Reliability and Normative Data for the Dynamic Visual Acuity Test for Vestibular Screening.

The purpose of this study was to determine reliability of computerized dynamic visual acuity (DVA) testing and to determine reference values for younger and older adults. A primary function of the vestibular system is to maintain gaze stability during head motion. The DVA test quantifies gaze stabilization with the head moving versus stationary. Commercially available computerized systems allow clinicians to incorporate DVA into their assessment; however, information regarding reliability and normative values of these systems is sparse. Forty-six healthy adults, grouped by age, with normal vestibular function were recruited. Each participant completed computerized DVA testing including static visual acuity, minimum perception time, and DVA using the NeuroCom inVision System. Testing was performed by two examiners in the same session and then repeated at a follow-up session 3 to 14 days later. Intraclass correlation coefficients (ICCs) were used to determine inter-rater and test-retest reliability. ICCs for inter-rater reliability ranged from 0.323 to 0.937 and from 0.434 to 0.909 for horizontal and vertical head movements, respectively. ICCs for test-retest reliability ranged from 0.154 to 0.856 and from 0.377 to 0.9062 for horizontal and vertical head movements, respectively. Overall, raw scores (left/right DVA and up/down DVA) were more reliable than DVA loss scores. Reliability of a commercially available DVA system has poor-to-fair reliability for DVA loss scores. The use of a convergence paradigm and not incorporating the forced choice paradigm may contribute to poor reliability.

Visual abilities in two raptors with different ecology.

Differences in visual capabilities are known to reflect differences in foraging behaviour even among closely related species. Among birds, the foraging of diurnal raptors is assumed to be guided mainly by vision but their foraging tactics include both scavenging upon immobile prey and the aerial pursuit of highly mobile prey. We studied how visual capabilities differ between two diurnal raptor species of similar size: Harris's hawks, Parabuteo unicinctus, which take mobile prey, and black kites, Milvus migrans, which are primarily carrion eaters. We measured visual acuity, foveal characteristics and visual fields in both species. Visual acuity was determined using a behavioural training technique; foveal characteristics were determined using ultra-high resolution spectral-domain optical coherence tomography (OCT); and visual field parameters were determined using an ophthalmoscopic reflex technique. We found that these two raptors differ in their visual capacities. Harris's hawks have a visual acuity slightly higher than that of black kites. Among the five Harris's hawks tested, individuals with higher estimated visual acuity made more horizontal head movements before making a decision. This may reflect an increase in the use of monocular vision. Harris's hawks have two foveas (one central and one temporal), while black kites have only one central fovea and a temporal area. Black kites have a wider visual field than Harris's hawks. This may facilitate the detection of conspecifics when they are scavenging. These differences in the visual capabilities of these two raptors may reflect differences in the perceptual demands of their foraging behaviours.

体操選手がとびひねり遂行中に行う視線移動パターン

This study aimed to clarify gaze shift patterns in gymnasts during a jump with a half turn by measuring horizontal eye-head movements. We also compared the gaze shift patterns of skilled gymnasts with those of non-gymnasts to examine the patterns characteristic of gymnasts. The participants were 10 skilled male gymnasts and 15 male non-gymnasts. Each participant performed a jump with a half turn, which is an aerial movement with a 180-degree longitudinal axis rotation. Eye movement during the jump was measured using electrooculography. The jump was recorded simultaneously with 2 high-speed digital cameras to determine angular horizontal head movement. Gaze was determined by combining eye and head movement data. The results showed that both gymnasts and non-gymnasts used 2 gaze shift patterns during the jump. In both of these patterns, gaze stabilized before takeoff and immediately before landing. However, in one pattern, termed the single-step gaze shift pattern, gaze moved directly from front to back, whereas in the other pattern, termed the multi-step gaze shift pattern, gaze shift toward the direction of rotation stopped several times even during midair rotation. The single-step gaze shift pattern was used more by gymnasts than by non-gymnasts. Taken together, these results show that gymnasts employ 2 gaze shift patterns when performing a jump with a half turn, but that the single-step gaze shift pattern may be more useful to gymnasts for controlling their movement than other gaze shift patterns.

Application of a computer vision technique to animal-borne video data: extraction of head movement to understand sea turtles’ visual assessment of surroundings

An animal-borne video recording system has recently been developed to study the behavior of free-ranging animals. In contrast to other types of sensor data (i.e., acceleration), video images offer the advantage of directly acquiring information without analysis. However, most previous findings have only been obtained through visual observation of image data. Here, we demonstrate a new method of data analysis for animal-borne videos using a computer vision technique referred to as template matching. As a case study, we tracked the horizontal head movements of green turtles (Chelonia mydas) to investigate how they move their heads to look around the underwater environment. Template matching allowed tracking of head movements with high accuracy (0.34 ± 0.12 % and 0.52 ± 0.29 % of the root-mean-square error on the x- and y-coordinates, respectively), high true (86.2 ± 8.1 %), and low false extraction rates (6.6 ± 8.4 %). However the program sometimes failed because the turtle’s head would move out of range of the video. During cruising swimming, green turtles did not significantly move their heads to one side, moving with a ratio of 50.5:49.5 (left: right). Green turtles moved their heads from side to side more widely and more slowly before (12.0 ± 4.6 point and 0.25 ± 0.03 Hz, respectively) and after taking a breath (27.5 ± 2.9 point and 0.27 ± 0.03 Hz) compared to during cruising swimming (8.4 ± 3.8 point and 0.32 ± 0.01 Hz). Before feeding, turtles moved their heads slowly (0.23 ± 0.03 Hz) and narrowly (9.3 ± 3.6 point). Our combined approach using video and gyro loggers revealed that when making a turn, turtles always turned their heads to the side 1.38 ± 0.77 s before turning their body. Our method enables researchers to quantitatively extract information regarding vision cognition and behavioral responses in green turtles in the wild that could not otherwise be obtained from other sensors used in previous studies. This new method using a combination of computer vision and bio-logging (e.g., gyroscope) can serve as a powerful tool in animal behavior and ecological studies.

Does Changing Vertical Disparity Induce Horizontal Head Movement?

Theoretically, one can estimate the direction of an object that is relative to the head using vertical disparity if the distance from the head to the object is known. However, several reports describe vertical disparity as having little or no effect on the perception of visual direction. It has been suggested, however, that the visual processes involved in action are different from those involved in perception, and the effect of visual disparity on action has not been investigated in previous studies. This study investigated the influence of vertical disparity on the stability of head direction as a motor response to visual information. We presented a stimulus consisting of horizontal lines with vertical size-disparity oscillation, and examined whether the stimulus affected the subject’s head movement. The results showed that the head movement in the condition of vertical size-disparity oscillation was not significantly different from that in the condition of no disparity oscillation. Our results suggest that, despite theoretical validity, vertical disparity is not used for controlling head movement.

Behavioral Responses of Cattle to Naturally Occurring Seasonal Populations of Horn Flies (Diptera: Muscidae) Under Rangeland Conditions.

The behavioral responses of cattle under the influence of naturally occurring seasonal horn fly, Haematobia irritans (L.), populations were evaluated under rangeland conditions. This study was replicated four times using 10 cows as the subsampling unit equipped with GPS collars scheduled to receive locational fixes every 5 min for 6 d prior to, and 6 d following horn fly insecticidal control application. Data derived from GPS collars were used to evaluate potential horn fly-induced behavioral modifications expressed during predawn, daytime, and nighttime periods. These data were used to analyze variables, which included distance travelled, daily area explored, vertical and horizontal head movements, and inferred activities such as resting, grazing, and walking. Horn fly populations were estimated using daily visual counts and were reduced significantly on animals following insecticidal application. There was no significant difference between treatment periods in any of the aforementioned analyzed variables. During the night-time hours estimated differences (pretreatment minus posttreatment) for distance travelled, area explored, and vertical head movements were 0.81 ± 0.46 km/d, 0.35 ± 0.21 km(2)/d, and 7.25 ± 5.30 counts/d, respectively. The implications of these observations are discussed.

Postnatal expression of TrkB receptor in rat vestibular nuclear neurons responsive to horizontal and vertical linear accelerations

We examined the maturation expression profile of tyrosine kinase B (TrkB) receptor in rat vestibular nuclear neurons that were activated by sinusoidal linear acceleration along the horizontal or vertical axis. The otolithic origin of Fos expression in these neurons was confirmed with labyrinthectomized controls and normal controls, which showed only sporadically scattered Fos-labeled neurons in the vestibular nucleus. In P4-6 test rats, no Fos-labeled neurons were found in the vestibular nucleus, but the medial and spinal vestibular neurons showed weak immunoreactivity for TrkB. The intensity of TrkB immunoreactivity in vestibular nuclear neurons progressively increased in the second postnatal week but remained low in adults. From P7 onward, TrkB-expressing neurons responded to horizontal or vertical otolithic stimulation with Fos expression. The number of Fos-labeled vestibular nuclear neurons expressing TrkB increased with age, from 13-43% in P7 rats to 85-90% in adult rats. Our results therefore suggest that TrkB/neurotrophin signaling plays a dominant role in modulating vestibular nuclear neurons for the coding of gravity-related horizontal head movements and for the regulation of vestibular-related behavior during postnatal development.

Submovement Composition of Head Movement

Limb movement is smooth and corrections of movement trajectory and amplitude are barely noticeable midflight. This suggests that skeletomuscular motor commands are smooth in transition, such that the rate of change of acceleration (or jerk) is minimized. Here we applied the methodology of minimum-jerk submovement decomposition to a member of the skeletomuscular family, the head movement. We examined the submovement composition of three types of horizontal head movements generated by nonhuman primates: head-alone tracking, head-gaze pursuit, and eye-head combined gaze shifts. The first two types of head movements tracked a moving target, whereas the last type oriented the head with rapid gaze shifts toward a target fixed in space. During head tracking, the head movement was composed of a series of episodes, each consisting of a distinct, bell-shaped velocity profile (submovement) that rarely overlapped with each other. There was no specific magnitude order in the peak velocities of these submovements. In contrast, during eye-head combined gaze shifts, the head movement was often comprised of overlapping submovements, in which the peak velocity of the primary submovement was always higher than that of the subsequent submovement, consistent with the two-component strategy observed in goal-directed limb movements. These results extend the previous submovement composition studies from limb to head movements, suggesting that submovement composition provides a biologically plausible approach to characterizing the head motor recruitment that can vary depending on task demand.

Nodding in dis/agreement: a tale of two cultures

Head movement is commonly used to communicate positive versus negative response. However, whereas in US culture, vertical head movement denotes positivity (nodding to say "yes") and horizontal head movement is associated with negativity (shaking heads to say "no"), in Bulgaria, this response pattern is reversed, that is, horizontal head movement means "yes" and vertical head movement means "no." Thus, these two cultures spatially "embody" agreement via different movement directions. We examined the effect of such cultural differences on cognitive processing that has no communicative intent by comparing ratings of likeability, brightness, and positive feeling associated with different color moving dots. Participants followed the dots' movement with their heads in a 2 (direction: vertical vs. horizontal) by 2 (speed: fast vs. slow) design. We found a two-way country by speed of movement interaction such that Bulgarian participants associated colors with more positive feeling when those were perceived in combination with slower head movement irrespective of movement direction. US participants, on the other hand, rated color dots as better mood-enhancing in combination with faster head movement. There was a similar two-way country by movement speed interaction for likeability ratings but none for brightness. Findings are discussed in terms of variability in gestural meaning and culture-specific embodiment patterns.

Disturbances in Cervico-Vestibulo-Oculomotor Interaction in Patients with Late Stages of Parkinson Disease

Cervico-vestibulo-oculomotor interactions in patients with Parkinson disease stages III-IV and healthy subjects were studied in horizontal head movement and gaze fixation on immobile and mobile targets. Significant changes in the amplitude, head movement frequency and asymmetry, eye movement amplitude, and phase mismatch between head and eye movements were revealed in patients in comparison to the normal.

Working distance and eye and head movements during near work in myopes and non‐myopes

Purpose: Reasons for the development and progression of myopia remain unclear. Some studies show a high prevalence of myopia in certain occupational groups. This might imply that certain head and eye movements lead to ocular elongation, perhaps as a result of forces from the extraocular muscles, lids or other structures. The present study aims to analyse head and eye movements in myopes and non‐myopes for near‐vision tasks.Methods: The study analysed head and eye movements in a cohort of 14 myopic and 16 non‐myopic young adults. Eye and head movements were monitored by an eye tracker and a motion sensor while the subjects performed three near tasks, which included reading on a screen, reading a book and writing. Horizontal eye and head movements were measured in terms of angular amplitudes. Vertical eye and head movements were analysed in terms of the range of the whole movement during the recording. Values were also assessed as a ratio based on the width of the printed text, which changed between participants due to individual working distances.Results: Horizontal eye and head movements were significantly different among the three tasks (p = 0.03 and p = 0.014, for eye and head movements, respectively, repeated measures ANOVA). Horizontal and vertical eye and head movements did not differ significantly between myopes and non‐myopes. As expected, eye movements preponderated over head movements for all tasks and in both meridians. A positive correlation was found between mean spherical equivalent and the working distance for reading a book (r = 0.41; p = 0.025).Conclusions: The results show a similar pattern of eye movements in all participating subjects, although the amplitude of these movements varied considerably between the individuals. It is likely that some individuals when exposed to certain occupational tasks might show different eye and head movement patterns.

Use of the Dynamic Visual Acuity Test as a screener for community-dwelling older adults who fall

Adequate function of the peripheral vestibular system, specifically the vestibulo-ocular reflex (VOR; a network of neural connections between the peripheral vestibular system and the extraocular muscles) is essential for maintaining stable vision during head movements. Decreased visual acuity resulting from an impaired peripheral vestibular system may impede balance and postural control and place an individual at risk of falling. Therefore, sensitive measures of the vestibular system are warranted to screen for the tendency to fall, alerting clinicians to recommend further risk of falling assessment and referral to a falling risk reduction program. Dynamic Visual Acuity (DVA) testing is a computerized VOR assessment method to evaluate the peripheral vestibular system during head movements; reduced visual acuity as documented with DVA testing may be sensitive to screen for falling risk. This study examined the sensitivity and specificity of the computerized DVA test with yaw plane head movements for identifying community-dwelling adults (58-78 years) who are prone to falling. A total of 16 older adults with a history of two or more unexplained falls in the previous twelve months and 16 age and gender matched controls without a history of falls in the previous twelve months participated. Computerized DVA with horizontal head movements at a fixed velocity of 120 deg/sec was measured and compared with the Dynamic Gait Index (DGI) a gold standard gait assessment measurement for identifying falling risk. Receiver operating characteristics (ROC) curve analysis and area under the ROC curve (AUC) were used to assess the sensitivity and specificity of the computerized DVA as a screening measure for falling risk as determined by the DGI. Results suggested a link between computerized DVA and the propensity to fall; DVA in the yaw plane was found to be a sensitive (92%) and accurate screening measure when using a cutoff logMAR value of >0.25.

An inherited episodic head tremor syndrome in Doberman pinscher dogs

Episodic head tremor anecdotally occurs in the Doberman pinscher dog breed, but it is not described in sufficient detail in the literature. We evaluated 87 Doberman pinschers affected with episodic head tremor and appropriate controls. The data analyzed were collected through detailed questionnaires, elaborate telephone interviews, and video recordings. Affected dogs underwent clinical, neurological, and laboratory examination, and a detailed diagnostic workup was conducted in 5 affected dogs. Pedigrees of affected dogs were collected and reviewed. The affected dogs expressed individual phenotypes of either horizontal or vertical head movements, but rarely did a dog exhibit head movements in both directions. There was considerable variation in duration (10 seconds to 3 hours; median: 3 minutes), frequency of occurrence (1-20 episodes/day; median: 2/day) of head tremor and length of the period without head tremor (1-1,800 days; median: 60 days). Subtle dystonic posturing of the head and neck during head tremor was evident on video recordings of 5 dogs. Certain exceptional conditions such as illness, surgery, some medications, heat, pseudopregnancy, or pregnancy triggered episodes. Two main important forms of episodic head tremor were identified: a familial early-onset form (age < 1 year) that affected littermates and a sporadic form. Affected dogs were traced back to 1 common sire, also including sporadic cases. Episodic head tremor is an inherited, paroxysmal movement disorder that affects the Doberman pinscher breed. Identification of the causative genes in the future will allow us to obtain a more detailed description of the syndrome.

Display Lag and Gain Effects on Vection Experienced by Active Observers

This study examined the effects of display lag and gain on visual self-motion perception (i.e., vection) in active observers. Our subjects viewed displays simulating self-motion in depth while physically oscillating their heads from side to side at approximately 1 Hz. Their horizontal head movements were recorded and incorporated into self-motion displays with four levels of added lag (0, 50, 100,and 200 ms; baseline system lag was 113 ms) and three levels of gain (i.e., subjects' head movements were either not incorporated into the display or were incorporated at either the same or twice the amplitude). At the end of each trial, subjects rated the strength of their perceived self-motion in depth. While increasing display lag above baseline by an additional 50 ms impaired vection strength ratings, increasing display lag beyond this level eventually improved vection. For example, 200 ms added display lag produced vection strength ratings that were similar to those found with the baseline lag. As expected, larger simulated display gains were shown to improve vection strength ratings regardless of the level of added display lag. We conclude that increasing display lag during active head oscillation only impairs vection until the resulting sensory conflict becomes too great to tolerate. Beyond this critical level of lag, the visual system appears to override or downplay such sensory conflicts.

A New Spin on the Vestibular Test Battery: Dynamic Visual Acuity and Subjective Visual Vertical

A New Spin on the Vestibular Test Battery: Dynamic Visual Acuity and Subjective Visual Vertical

Music is in the Muscle: How Embodied Cognition May Influence Music Preferences

Music is Intimately Connected with Body movements. Until recently, research has almost exclusively examined the impact of music on body movements. Yet findings on embodied cognition in other domains suggest that the influence might also work in the opposite direction: Real or imagined body movements during music listening may codetermine music preferences. We had participants listen to music and concurrently activate muscles whose innervation has been shown to be associated with "positive" and "negative" affect (activation vs. inhibition of smiling muscles, vertical vs. horizontal head movements, and arm flexion vs. arm extension). Activation of the positively associated muscle groups led to higher preference ratings for the music pieces than activation of the negatively associated ones. A first exploration of candidate explanations for the effect suggests that it is most likely due to conditioning processes. It is concluded that body movements, both real and imagined, may play an important role in the development of music preferences.

Adaptation behaviour of local and rangeland cattle relocated to a temperate agricultural pasture

Relocating cattle from rangeland properties to agricultural pastures in southern Western Australia allows producers to improve year-round continuity of feed supply in their beef cattle businesses, and can reduce substantially the time taken to grow animals to meet market specifications. In this study the behaviour and growth of two groups of young cattle that were sourced from different locations was evaluated after they were transferred to a new extensive grazing system. In Experiment 1, 122 Limousin-cross heifers that were raised in the agricultural region of Western Australia (AR cattle) were transferred to the experimental site from a neighbouring property (~10 km away). In Experiment 2, 95 Brahman-cross heifers that were raised in the rangelands of Western Australia (RR cattle) were transferred to the experimental site. Animal growth and behaviour were analysed across time and differences in the time-course of behavioural changes between the groups were compared. Rate of liveweight gain in the AR cattle remained consistent (~1.2 kg/day) during the experiment. There was an increase in horizontal (16%; P &lt; 0.001) and vertical (12%; P = 0.002) head movement in AR cattle over the first several weeks after relocation, indicative of increased grazing activity, but there was little change in other behaviours over the duration of the experiment. In contrast, the RR cattle had reduced growth during the first 4 weeks after relocation (P &lt; 0.001). From weeks 2–4 weight gain in RR cattle was 0.31 kg/day, approximately one-quarter of their average daily gain attained 4 weeks later. During the first 6 weeks, RR cattle showed behavioural changes indicative of adaptation, including a 61% increase in horizontal head movements, suggesting more grazing activity. The paddock area utilised daily by RR cattle was 32% higher in week 6 compared with week 1, and during daylight hours (0600–1900 hours) they began to travel more (23%) and spent more time active (16%). We conclude that rangeland-raised Bos indicus heifers take from 4 to 6 weeks to adapt from their previous large paddocks/natural plant environment to a new temperate agricultural environment. Our results suggest that the cause of lost productivity in rangeland cattle when they are relocated to a temperate pasture is at least in part due to initial lower grazing activity as they become familiar with the new environment.