SENSASI dan PERSEPSI

Psikologi Umum II – Genap 2006

SENSASI

• Bersifat pribadi

• Merupakan stimulasi thd organ/indera kita

• Masing-masing orang memiliki sensasi yang berbeda satu sama lain.

• Melibatkan penyerapan energi, seperti cahaya atau suara, yang dilakukan oleh organ sensori misalnya mata dan telinga.

Sensasi

Proses menerima energi rangsangan dari lingkungan luar.

Rangsangan terdiri atas energi fisik, seperti cahaya, saura, dan panas

Rangsangan dideteksi melalui organ indra, rangsangan diterima berbentuk energi fisik yang diubah menjadi impuls listrik (transduksi)

Persepsi

• Proses mengatur dan mengartikan informasi sensoris untuk memberikan makna.

• Merupakan perwakilan internal dari dunia luar

• Bottom up processing reseptor sensoris mencatat informasi mengenai lingkungan luar dan mengirimkannya ke otak untuk analisis dan interpretasi, dipicu o/rangsangan

..lanjut

• Top Bottom processing dipicu oleh pemrosesan kognisi pada tingkat yg lebih tinggi di otak.

• Proses ini adalah ketika kita merasakan apa yang sedang terjadi dan mengaplikasikan kerangka kerja tersebut pada informasi dr dunia luar. Mencakup pengetahuan, sistem, kepercayaan, dan juga harapan kita

RESEPTOR SENSORI DAN OTAK

• Merupakan sel-sel yang terspesialisasi untuk mendeteksi informasi rangsangan dan memancarkannya ke saraf sensoris dan otak.

• Organ indra dan reseptor sensoris dimasukkan dalam beberapa kelas utama berdasarkan tipe energi yang dipancarkan, al: resepsi cahaya, resepsi mekanik, dan komereseptor.

Teori Pendeteksian Sinyal

• Teori pendeteksian sinyal, menitikberatkan pada pengambilan keputusan mengenai rangsangan pada saat adanya ketidakpastian. Terdapat faktor eksternal yang mempengaruhi seperti kelelahan, harapan, dan keterdesakan.

• Akuisisi informasi, info yg diterima otak

• Kriteria, dasar permbuatan keputusan

MEMPERSEPSI RANGSANGAN SENSORIS

ATENSI

1. Atensi selektif, memfokuskan pada aspek spesifik sebuah pengalaman dan mengabaikan aspek yang lain

2. Atensi tidak hanya selektif tetapi juga dapat dialihkan.

ABSOLUTE THRESHOLD

VISUAL SYSTEM

Demonstration of the blind spot

Process Dark Adaptation

Hermann grid to see dark spot

Trichromatic Theory

Demontration of Complementary Afterimage

Distal & Proximal Stimuli

Auditory system 1.Ossicle. 2. Semicircular canal. 3. Cochlea. 4. Auditory nerve 5. Eustachian tube

6.Midle ear. 7. Ear drum 8. External ear canal

Sound waves funnel into the outer ear - the flap of skin and cartilage on the side of the head. They pass along a narrow tube, the ear canal, to a small patch of rubbery skin at its end, the

eardrum. The sound waves bounce off the eardrum and make it shake to and fro, or vibrate. The eardrum is connected to a row of three tiny bones linked together, the hammer, anvil and stirrup.

The vibrations pass along these bones. The stirrup presses against a small, fluid-filled, snail-shaped part, the cochlea, deep inside the ear. The vibrations pass as ripples into the fluid inside the cochlea. Here, they shake thousands of tiny hairs that stick into the fluid from hair cells. As

the hairs shake, the hair cells make nerve signals, which go along the auditory nerve to the hearing centre of the brain.  

Taken from Medical Facts for Pilots

The Auditory Senses

Emotions andBehaviors

Organization andInterpretation

Selective Attention

Perceptual Process Model

Feeling Hearing Seeing Smelling Tasting

Environmental Stimuli

Olfactory system. 1. Olfactory bulb. 2. nasal cavity. 3. Brain. 4. Olfactory epithelium 5. Vomeronasal organ. 6. Ions. 7 Glomeruli. *. Axon. 9. To olfactory cortex

Inside each side of the nose is an air chamber, the nasal cavity. Air comes in through the nostril and flows down, around the rear of the roof of the mouth, into the throat. But

when you sniff, air swirls up into the top of the cavity. Here is a small patch of about 10 million specialised olfactory (smelling) cells. They have long micro-hairs, or cilia,

sticking out from them. Odour particles in the air stick on to the cilia and make the olfactory cells produce nerve signals, which travel to the olfactory bulb. This is a pre-

processing centre that partly sorts the signals before they go along the olfactory tract to the brain where they are

Images from Scientific American by Roberto Osti and J.G. Hildebrand.

The Olfactory Sense

The tongue is covered with dozens of pimple-like projections called papillae. These grip and move food when you chew. Around the sides of the papillae are about 10,000 microscopic taste buds. Different parts of the tongue are sensitive to different flavours: sweet, salt, sour and bitter.

Image from The Human Body

The Gustatory Sense

The sense of touch is the name given to a network of nerve endings that reach just about every part of our body. These sensory nerve endings are located just below the skin and register light and heavy pressure on the skin and also differences in temperature. These nerve endings gather information and send it to the brain

The Touch Sense

Emotions andBehaviors

Organization andInterpretation

Selective Attention

Perceptual Process Model

Feeling Hearing Seeing Smelling Tasting

Environmental Stimuli

A Poster for Trained Seal Act

Feature Analysis in Form Perception

The Principle of Figure & Ground

Figure Ground Relationships

Bentuk pemisahan paling primitif yang dilakukan oleh pikiran manusia

– Antara Figur dan Background

– Figur lebih terlihat karena terdapat Background

Figure Ground Relationships

• Contoh ilusi yang ada :– Necker Cube

Reverses Front and Back– Goblet Versus Person

• Kita mempelajari menganai figur yang ada bukan mengenai background

Gestalt Principles of Perceptual Organization

The Law of Proximity

• Elemen yang ada dikelompokkan berdasar kedekatan (proximity) atau kesamaan (nearness)

• Corollary• The Closer Together Two Elements Are, the More

Likely They Are Grouped Together

• Ex : We Hear or Organize Speech With Pauses

The Law of Proximity

Examples of Proximity as a Grouping Factor:

… … …

………

. . .

. . .. . . . . . . . .

The Law of Similarity

• Grouping By Size or Brightness

• Similar Factors in Auditory Grouping– Pitch– Background Noise Differentiation– We Can Talk and Hear at a Noisy Party

The Law of Common Direction

• Common Direction Means “Common Fate” (keumuman)

• Waves

• Extrapolating the Movement of Certain Items

The Law of Simplicity

• The Person shall organize the field into simple figures

- Good Gestalts

- Symmetry

- Regularity

- Smoothness

Reversible Figure

Shape Constancy

Explaining The Muller-Lyer Illusion

Four Geometric Illusions

• Refleks adalah gerak fisik otomatis yang dilakukan tanpa melalui kendali pikiran.

Contoh : bola