CogniFit - Perception

What is perception?

Perception is the ability to capture, process, and actively make sense of the information that our senses receive. It is the cognitive process that makes it possible to interpret our surroundings with the stimuli that we receive throughout sensory organs. This important cognitive ability is essential to our daily lives because it makes it possible to understand our surroundings. It's possible to train and improve perception with cognitive stimulation. It is an active process and requires that we process information with both "bottom-up" and "top-down" processing, meaning that we are not only directed by the stimuli that we receive (passive, bottom-up processing) but that we expect and anticipate certain stimuli that control perception (active, top-up processing).

Types of Perception and Neuroanatomy

Perception is a complex process that allows us to connect with the surrounding world. Classically, it is divided in five senses:

• Visual: The ability to see and interpret light information within the visible spectrum that arrives to our eyes. The area of the brain responsible for visual perception is the occipital lobe (primary visual cortex V1 and secondary visual cortex V2).
• Hearing: Ability to receive and interpret information that arrives to our ears by audible frequency waves through the air or another mean (sound). The brain part in charge of the basic stage of auditory perception is the temporal lobe (primary auditory cortex A1 and secondary auditory cortex A2).
• Touch, somatosensory or haptic : The capacity to interpret information of pressure and vibration received on the surface of our skin. The parietal lobe is the part of the brain responsible for the basic stages in haptic perception (primary somatosensory cortex S1 and secondary somatosensory cortex S2).
• Smell or olfactory : The ability to interpret information of chemical substances dissolved in the air (smell). Basic stages of the olfactory perception are done by the olfactory bulb (primary olfactory cortex) and the piriform cortex (secondary olfactory cortex).
• Taste: The ability to interpret information from chemical substances dissolved in saliva (taste). The main brain areas in control of the basic stages are the primary taste areas G1 (postcentral inferior gyrus, parietal ventral lobe, anterior insula, fronto-parietal medial operculum) and secondary taste areas G2 (caudolateral frontal orbital cortex and anterior cingulate cortex).

Phases of Perception

Perception is not a single process that happens spontaneously. Instead, it is a series of phases that take place in order for the correct appreciation of stimuli to occur. For example, to perceive visual information, it's not enough for light to reflect off an object and this stimulating our retinal receptor cells for them to send this information to the correct brain areas. For it to happen, all of that is necessary. However, it is an active process, where we have to select, organize and interpret the information sent to the brain:

• Selection: The number of stimuli we are exposed daily exceeds our capacity. For this reason, we need to filter and choose the information we want to perceive. This selection is done through our attention, experiences, necessities and preferences.
• Organization: Once we know what to perceive, we need to gather the stimuli in groups in order to give them meaning. In perception, there is synergy, since it is an overall recognition of what is perceived and it can't be reduced to separate stimuli characteristics. According to Gestalt principles, stimuli organization is not random but instead it follows specific criteria.
• Interpretation: When we have organized all the selected stimuli, we then proceed to give them meaning, completing the perception process. The interpretation process is modulated by our experience and expectations.

Examples of Perception

• It's important to identify on time any perceptive problem that the student might have. This will allow us to apply the means necessary so no auditory information is lost (what the professor says) or visual information (the text on the board and books).
• A correct perception helps workers do their job efficiently. Artists are a clear example of the importance of it in the professional world. However, any job requires, in a greater or lesser manner, some type of perception: sweepers, taxi drivers, designers, policemen, cashiers, builders, etc.
• Perceiving road signs, as well as sounds from your own car, is essential in driving safely.
• It makes it possible for us to advance in our environment and interact with it. Grocery shopping, playing a video game, cooking and doing laundry require that we use all our senses.

Agnosia and other disorders regarding perception

In some circumstances, perception may not reflect reality without this being pathological. These "failures" in perception may be illusions or hallucinations. Illusions refer to an erroneous interpretation of a real external stimulus, while hallucinations consist of an erroneous perception without the presence of a real external stimulus. These perceptual experiences can happen with any existing pathologies, they are mainly caused by physiological or cognitive characteristics of the system or altered states (substance abuse or sleep). An example of illusion would be the well-known optical illusions (perceiving two identical colours differently, perceiving movement in a static image, etc.). The most common hallucinations are hypnagogic (when you are falling asleep and perceive a figure, sound or feel like someone is touching you), hypnopompic (same sensations but when you are waking up) and the ones derived from consuming hallucinogenic drugs (such as LSD or hallucinogenic mushrooms that provoke more elaborate hallucinations). Nonetheless, illusions and hallucinations can also be pathological, related with schizophrenia, psychosis episodes, delusional ideas.

Perception can also be altered by damage to our sensory organs (for example, an eye injury), damage in the pathways that take the sensory information to the brain (for example, glaucoma) or in the brain areas in charge of perception (for example, an injury in the occipital cortex). A damage in any of these three points can alter the normal perception of stimuli.

The most common perception disorder is Agnosia. This disorder entails a difficulty in directing and controlling perception, as well as behaviour in general. There are two types: Perceptive visual agnosia (can see parts of an object but is incapable of understanding the object as a whole) and Associative visual agnosia (understands the object as a whole but can place what object is it). It's difficult to understand it through these disorders since even though they can see, for them it is a similar sensation to being blind. There are also more specific disorders, such as akinetopsia (inability to see movement), achromatopsia (inability to see colours), prosopagnosia (inability to recognize familiar faces), auditive agnosia (inability to recognize an object by sound, and, in the case of verbal information, person with agnosia wouldn't be able to recognize the language as such), amusia (inability to recognize or reproduce musical tones or rhythms). These disorders are produced by brain damages such as ictus, brain trauma or, even a neurodegenerative disease.

How Can you Measure and Assess Perception?

Perception evaluation can be of great help in different aspects of life: in academic fields (to know if a student needs extra help to perceive the information in class), in clinical fields ( to know if a patient will present difficulties in relation to the environment)or in professional fields (to know if a worker needs support due to a perceptive problem).

Through a complete neuropsychological evaluation we can measure it and other cognitive abilities efficiently and reliably.

CogniFit uses a number of classic tests as a basis for many of its tasks, like the Stroop Test, the Test of Variables of Attention (TOVA), the Test of Memory Malingering (TOMM), Continuous Performance Test (CPT), Hooper Visual Organization Task (VOT), the NEPSY test (Korkman, Kirk, Kemp, 1998). In addition to perception, these tests also measure naming, contextual memory, response time, working memory, updating, visual memory, processing speed, divided attention, focused attention, hand-eye coordination, shifting, inhibition, and visual scanning.

• Identification Test COM-NAM: Objects will be presented either with an image or a sound. The user has to say how the object was presented (image or sound) the last time it was presented. If it is the first time that the object is presented, the user will have to choose the corresponding option.
• Programming Test VIPER-PLAN: Move the ball through the maze in as few moves and as quickly as possible.
• Concentration Test VISMEM-PLAN: Stimuli on the screen will illuminate and play a sound in a certain order. As the stimuli is being presented, the user must pay close attention so that they will be able to repeat it in the same order that it was presented.
• Inquiry Test REST-COM: Objects will appear for a short period of time. The user will later have to choose the option that corresponds to the objects presented as quickly as possible.
• Decoding Test VIPER-NAM: Images will appear on the screen for a short period of time before they disappear. Four letters will then appear on the screen, one of which corresponds to the first letter of the object shown. The user will have to choose the correct letter as quickly as possible.
• Speed Test REST-HECOOR: A blue square will appear on the screen. The user must click as quickly and as many times as possible in the middle of the square. The more times the user clicks, the higher the score.
• Recognition Test WOM-REST: A series of three objects will appear on the screen. The user must memorize the order in which they are displayed and later choose the correct order from a selection.
• Resolution Test REST-SPER: A number of moving stimuli will appear on the screen. The user has to click on the target stimuli as quickly as possible, without clicking on irrelevant stimuli

How Can you Recover or Improve Perception?

Every cognitive skill, including perception, can be trained and improved.

Brain plasticity is the basis of perception rehabilitation and other cognitive skills. The brain and its neural connections can be strengthened by challenging and working them, so by frequently training these skills, the brain structures related to it will become stronger.

CogniFit was created by a team of professionals specialized in the area of neurogenesis and synaptic plasticity, which is how we were able to create a personalized cognitive stimulation program that would be tailored to the needs of each user. This program starts with an evaluation to assess perception and a number of other fundamental cognitive domains, and based on the results, creates a personalized brain training program for each user. The program automatically collects the data from this initial cognitive assessment, and, with the use of sophisticated algorithms, creates a program that works on improving the user's cognitive weaknesses and training their cognitive strengths.

The key to improving it is adequate and consistent training. CogniFit has professional assessment and training tools to help both individuals and professionals optimize this function. It only takes 15 minutes a day, two to three times a week.

CogniFit's assessments and stimulation programs are available online and can be practiced on most computers and mobile devices. The program is made up of fun, interactive brain games, and at the end of each training session, the user automatically receives a detailed graph highlighting the user's cognitive progress.

References: Evelyn Shatil, Jaroslava Mikulecká, Francesco Bellotti, Vladimír Burěs - Novel Television-Based Cognitive Training Improves Working Memory and Executive Function - PLOS ONE July 03, 2014. 10.1371/journal.pone.0101472 Korczyn AD, Peretz C, Aharonson V, et al. - Computer based cognitive training with CogniFit improved cognitive performance above the effect of classic computer games: prospective, randomized, double blind intervention study in the elderly. Alzheimer's & Dementia: The Journal of the Alzheimer's Association 2007; 3(3):S171. Peretz C, Korczyn AD, Shatil E, Aharonson V, Birnboim S, Giladi N. - Computer-Based, Personalized Cognitive Training versus Classical Computer Games: A Randomized Double-Blind Prospective Trial of Cognitive Stimulation - Neuroepidemiology 2011; 36:91-9. Korczyn AD, Peretz C, Aharonson V, et al. - Computer based cognitive training with CogniFit improved cognitive performance above the effect of classic computer games: prospective, randomized, double blind intervention study in the elderly. Alzheimer's & Dementia: The Journal of the Alzheimer's Association 2007; 3(3):S171. Shatil E, Korczyn AD, Peretz C, et al. - Improving cognitive performance in elderly subjects using computerized cognitive training - Alzheimer's & Dementia: The Journal of the Alzheimer's Association 2008; 4(4):T492. Haimov I, Shatil E (2013) Cognitive Training Improves Sleep Quality and Cognitive Function among Older Adults with Insomnia. PLOS ONE 8(4): e61390. doi:10.1371/journal.pone.0061390 Thompson HJ, Demiris G, Rue T, Shatil E, Wilamowska K, Zaslavsky O, Reeder B. - Telemedicine Journal and E-health Date and Volume: 2011 Dec;17(10,):794-800. Epub 2011 Oct 19.